Metal ligand-containing prepolymers, methods of synthesis, and compositions thereof

ABSTRACT

Metal ligand-containing prepolymers, compositions containing metal ligand-containing prepolymers, methods of synthesizing metal ligand-containing prepolymers and the use of metal ligand-containing prepolymers in aerospace sealant applications are disclosed. The metal ligand-containing prepolymers have metal ligands incorporated into the backbone of the prepolymer. Cured sealant compositions comprising the metal ligand-containing prepolymers exhibit enhanced properties suitable for aerospace sealant applications.

This application is a continuation of U.S. application Ser. No.14/065,554, filed on Oct. 29, 2013, which is a continuation-in-part ofU.S. application Ser. No. 13/923,903, filed on Jun. 21, 2013, issued asU.S. Pat. No. 8,952,124, a continuation-in-part of U.S. application Ser.No. 13/923,941 filed on Jun. 21, 2013, and a continuation-in-part ofU.S. application Ser. No. 13/833,827 filed on Mar. 15, 2013, each ofwhich is incorporated by reference in its entirety.

FIELD

The present disclosure relates to metal ligand-containing prepolymers,compositions containing metal ligand-containing prepolymers, methods ofsynthesizing metal ligand-containing prepolymers, and uses of metalligand-containing prepolymers in aerospace sealant applications. Themetal ligand-containing prepolymers include, for example, metal ligandssuch as bis(sulfonyl)alkanol, acetylacetonate, or hydroxypyridinonegroups incorporated into the backbone of a prepolymer such aspolythioether prepolymers or polysulfide prepolymers.

BACKGROUND

Sealants useful in aerospace and other applications must satisfydemanding mechanical, chemical, and environmental requirements. Forexample, it is desirable that aerospace sealants function over atemperature range such as from about −67° F. to about 360° F. andexhibit fuel resistance. As disclosed in U.S. application Ser. No.13/923,903 and U.S. application Ser. No. 13/923,941, sealants formedusing polythioether prepolymers having bis(sulfonyl)alkanol groupsincorporated into the backbone and/or present as terminal groups exhibitenhanced adhesion to metal surfaces and meet other performancerequirements for aerospace sealants.

Aerospace vehicles often include lightweight surfaces made from aluminumand titanium alloys. Previous work by the inventors demonstrated thatcompositions having improved adhesion to these surfaces could berealized by using prepolymers in which a bis(sulfonyl)alkanol moiety wasincorporated into the backbone of the prepolymer. Expanding this work toinclude other metal ligands provides additional opportunities forenhancing surface adhesion to aerospace and other surfaces.

Sulfur-containing prepolymers having improved adhesion to metal surfacesand that meet other performance requirements for use in aerospace andother applications are desired.

SUMMARY

In a first aspect, metal ligand-containing prepolymers are providedcomprising a metal ligand incorporated into a backbone of theprepolymer.

In a second aspect, thiol-terminated metal ligand-containingpolythioethers are provided comprising the reaction product of reactantscomprising:

(a) a thiol-terminated polythioether comprising a thiol-terminatedpolythioether of Formula (18a), a thiol-terminated polythioether ofFormula (18b), or a combination thereof:HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a){HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′—}_(z)B  (18b)

wherein:

-   -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, or —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ independently comprises hydrogen or methyl; and        -   each X independently comprises —O—, —S—, or —NR⁵—, wherein            R⁵ is selected from hydrogen and methyl;    -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or        —[(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6; and    -   B represents a core of a z-valent polyfunctionalizing agent        B(—V)_(z) wherein:        -   z is an integer from 3 to 6;        -   each V is a group comprising a terminal group reactive with            terminal thiol groups; and    -   each —V′— is derived from the reaction of —V with a thiol; and

(b) a metal chelating agent R⁹-L-R⁹, wherein each R⁹ independentlycomprises a terminal group reactive with a thiol; and -L- comprises ametal ligand.

In a third aspect, thiol-terminated metal ligand-containingpolythioether prepolymers are provided comprising the reaction productof reactants comprising:

(a) a thiol-terminated metal ligand-containing polythioether comprisinga thiol-terminated metal ligand-containing polythioether of Formula(29a), a thiol-terminated metal ligand-containing polythioether ofFormula (29b), or a combination thereof:H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a){H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′-}_(z)B  (29b)wherein:

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:        -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ independently comprises hydrogen or methyl; and            -   each X independently —O—, —S—, or —NR⁵—, wherein R⁵ is                selected from hydrogen and methyl;        -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or            —[(—CHR₃—)_(s)—X—]_(q)—(—CHR₃—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6;

B represents a core of a z-valent, alkenyl-terminatedpolyfunctionalizing agent B(—V)_(z) wherein:

-   -   z is an integer from 3 to 6; and    -   each V is a group comprising a terminal alkenyl group; and

each —V′— is derived from the reaction of —V with a thiol; and

(b) a polyalkenyl compound.

In a fourth aspect, methods of preparing a thiol-terminated metalligand-containing polythioethers of Formula (29a) are provided,comprising reacting (N+1) moles of a thiol-terminated polythioether ofFormula (18a) with (N) moles of a metal chelating agent R⁹-L-R⁹:H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a)wherein:

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:    -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, or —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ independently comprises hydrogen or methyl; and        -   each X independently comprises —O—, —S—, or —NR⁵—, wherein            R⁵ comprises hydrogen or methyl; and    -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or        —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and    -   p is an integer from 2 to 6.

In a fifth aspect, methods of preparing a thiol-terminated metalligand-containing polythioethers of Formula (29b) are providedcomprising reacting (z) moles of a thiol-terminated metalligand-containing polythioether of Formula (29a) with one (1) mole of apolyfunctionalizing agent B {V}_(z):{H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′—}_(z)B  (29b)H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)wherein,

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:        -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ independently comprises hydrogen or methyl; and            -   each X independently comprises —O—, —S—, or —NR⁵—,                wherein R⁵ comprises hydrogen or methyl;        -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³, and            X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6; and

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a terminal group reactive with a        terminal thiol group; and    -   each —V′— is derived from the reaction of —V with a thiol.

In a sixth aspect, compositions comprising metal ligand-containingprepolymers are provided.

In a seventh aspect, cured sealant comprising compositions comprisingmetal ligand-containing prepolymers are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table showing calculated energies for the interaction ofligands with aluminum (III) surfaces described in Example 4.

Reference is now made to certain embodiments of compositions andmethods. The disclosed embodiments are not intended to be limiting ofthe claims. To the contrary, the claims are intended to cover allalternatives, modifications, and equivalents.

DETAILED DESCRIPTION Definitions

For purposes of the following description, it is to be understood thatembodiments provided by the present disclosure may assume variousalternative variations and step sequences, except where expresslyspecified to the contrary. Moreover, other than in the examples, orwhere otherwise indicated, all numbers expressing, for example,quantities of ingredients used in the specification and claims are to beunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired properties to beobtained. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges encompassed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of about 1 and the recited maximumvalue of about 10, that is, having a minimum value equal to or greaterthan about 1 and a maximum value of equal to or less than about 10.Also, in this application, the use of “or” means “and/or” unlessspecifically stated otherwise, even though “and/or” may be explicitlyused in certain instances.

A dash (“-”) that is not between two letters or symbols is used toindicate a point of covalent bonding for a substituent or between twoatoms. For example, the chemical group —CONH₂ is covalently bonded toanother chemical moiety through the carbon atom.

An “acetylacetonate group” refers to a group having the structure ofFormula (1):

In certain embodiments, an acetylacetonate refers to a metal chelatingagent comprising an acetylacetonate ligand and one or more reactivefunctional groups. In certain embodiments, the one or more reactivefunctionals can be reactive with a thiol group such as an epoxy group,an alkenyl group, a Michael acceptor group, or a group comprising asaturated carbon bearing a leaving group that are well suited fornucleophilic substitution such as, for example, —Cl, —Br, —I, —OSO₂CH₃(mesylate), —OSO₂—C₆H₄—CH₃ (tosylate), etc.

“Alkanearene” refers to a hydrocarbon group having one or more aryland/or arenediyl groups and one or more alkyl and/or alkanediyl groups,where aryl, arenediyl, alkyl, and alkanediyl are defined herein. Incertain embodiments, each aryl and/or arenediyl group(s) is C₆₋₁₂,C₆₋₁₀, and in certain embodiments, phenyl or benzenediyl. In certainembodiments, each alkyl and/or alkanediyl group(s) is C₁₋₆, C₁₋₄, C₁₋₃,and in certain embodiments, methyl, methanediyl, ethyl, orethane-1,2-diyl. In certain embodiments, the alkanearene group is C₄₋₁₈alkanearene, C₄₋₁₆ alkanearene, C₄₋₁₂ alkanearene, C₄₋₈ alkanearene,C₆₋₁₂ alkanearene, C₆₋₁₀ alkanearene, and in certain embodiments, C₆₋₉alkanearene.

Examples of alkanearene groups include diphenyl methane.

“Alkanearenediyl” refers to a diradical of an alkanearene group. Incertain embodiments, the alkanearenediyl group is C₄₋₁₈ alkanearenediyl,C₄₋₁₆ alkanearenediyl, C₄₋₁₂ alkanearenediyl, C₄₋₈ alkanearenediyl,C₆₋₁₂ alkanearenediyl, C₆₋₁₀ alkanearenediyl, and in certainembodiments, C₆₋₉ alkanearenediyl. Examples of alkanearenediyl groupsinclude diphenyl methane-4,4′-diyl.

“Alkanediyl” refers to a diradical of a saturated, branched orstraight-chain, acyclic hydrocarbon group, having, for example, from 1to 18 carbon atoms (C₁₋₁₈), from 1 to 14 carbon atoms (C₁₋₁₄), from 1 to6 carbon atoms (C₁₋₆), from 1 to 4 carbon atoms (C₁₋₄), or from 1 to 3hydrocarbon atoms (C₁₋₃). It will be appreciated that a branchedalkanediyl has a minimum of three carbon atoms. In certain embodiments,the alkanediyl is C₂₋₁₄ alkanediyl, C₂₋₁₀ alkanediyl, C₂₋₈ alkanediyl,C₂₋₆ alkanediyl, C₂₋₄ alkanediyl, and in certain embodiments, C₂₋₃alkanediyl. Examples of alkanediyl groups include methane-diyl (—CH₂—),ethane-1,2-diyl (—CH₂CH₂—), propane-1,3-diyl and iso-propane-1,2-diyl(e.g., —CH₂CH₂CH₂— and —CH(CH₃)CH₂—), butane-1,4-diyl (—CH₂CH₂CH₂CH₂—),pentane-1,5-diyl (—CH₂CH₂CH₂CH₂CH₂—), hexane-1,6-diyl(—CH₂CH₂CH₂CH₂CH₂CH₂—), heptane-1,7-diyl, octane-1,8-diyl,nonane-1,9-diyl, decane-1,10-diyl, dodecane-1,12-diyl, and the like.

“Alkanecycloalkane” refers to a saturated hydrocarbon group having oneor more cycloalkyl and/or cycloalkanediyl groups and one or more alkyland/or alkanediyl groups, where cycloalkyl, cycloalkanediyl, alkyl, andalkanediyl are defined herein. In certain embodiments, each cycloalkyland/or cycloalkanediyl group(s) is C₃₋₆, C₅₋₆, and in certainembodiments, cyclohexyl or cyclohexanediyl. In certain embodiments, eachalkyl and/or alkanediyl group(s) is C₁₋₆, C₁₋₄, C₁₋₃, and in certainembodiments, methyl, methanediyl, ethyl, or ethane-1,2-diyl. In certainembodiments, the alkanecycloalkane group is C₄₋₁₈ alkanecycloalkane,C₄₋₁₆ alkanecycloalkane, C₄₋₁₂ alkanecycloalkane, C₄₋₈alkanecycloalkane, C₆₋₁₂ alkanecycloalkane, C₆₋₁₀ alkanecycloalkane, andin certain embodiments, C₆₋₉ alkanecycloalkane. Examples ofalkanecycloalkane groups include 1,1,3,3-tetramethylcyclohexane andcyclohexylmethane.

“Alkanecycloalkanediyl” refers to a diradical of an alkanecycloalkanegroup. In certain embodiments, the alkanecycloalkanediyl group is C₄₋₁₈alkanecycloalkanediyl, C₄₋₁₆ alkanecycloalkanediyl, C₄₋₁₂alkanecycloalkanediyl, C₄₋₈ alkanecycloalkanediyl, C₆₋₁₂alkanecycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, and in certainembodiments, C₆₋₉ alkanecycloalkanediyl. Examples ofalkanecycloalkanediyl groups include1,1,3,3-tetramethylcyclohexane-1,5-diyl and cyclohexylmethane-4,4′-diyl.

“Alkenyl” group refers to a group having the structure —CR═CR₂ where thealkenyl group is a terminal group and is bonded to a larger molecule. Insuch embodiments, each R may be selected from, for example, hydrogen andC₁₋₃ alkyl. In certain embodiments, each R is hydrogen and an alkenylgroup has the structure —CH═CH₂.

“Alkoxy” refers to a —OR group where R is alkyl as defined herein.Examples of alkoxy groups include methoxy, ethoxy, n-propoxy,isopropoxy, and n-butoxy. In certain embodiments, the alkoxy group isC₁₋₈ alkoxy, C₁₋₆ alkoxy, C₁₋₄ alkoxy, and in certain embodiments, C₁₋₃alkoxy.

“Alkyl” refers to a monoradical of a saturated, branched orstraight-chain, acyclic hydrocarbon group having, for example, from 1 to20 carbon atoms, from 1 to 10 carbon atoms, from 1 to 6 carbon atoms,from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms. It will beappreciated that a branched alkyl has a minimum of three carbon atoms.In certain embodiments, the alkyl group is C₁₋₆ alkyl, C₁₋₄ alkyl, andin certain embodiments, C₁₋₃ alkyl. Examples of alkyl groups includemethyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl,n-hexyl, n-decyl, tetradecyl, and the like. In certain embodiments, thealkyl group is C₁₋₆ alkyl, C₁₋₄ alkyl, and in certain embodiments, C₁₋₃alkyl. It will be appreciated that a branched alkyl has at least threecarbon atoms.

A “bis(sulfonyl)alkanol group” refers to a group having the generalformula:—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—  (2)where each R¹⁰ is independently selected from C₁₋₃ alkanediyl andsubstituted C₁₋₃ alkanediyl, where the one or more substituent groups is—OH. In certain embodiments, a bis(sulfonyl)alkanol group has thestructure —CH₂—CH₂—S(O)₂—R¹—CH(—OH)—R¹⁰—S(O)₂—CH₂—CH₂—.

In certain embodiments, a “bis(sulfonyl)alkanol group” can be amonovalent bis(sulfonyl)alkanol group or a divalent bis(sulfonyl)alkanolgroup. In certain embodiments, a monovalent bis(sulfonyl)alkanol can bea terminal bis(sulfonyl)alkanol group such as a“1-(ethylenesulfonyl)-n-(vinylsulfonyl)alkanol group.” A terminalbis(sulfonyl)alkanol group can be derived from the reaction of abis(sulfonyl)alkanol and can have a terminal moiety with the generalstructure —R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R⁸ where R^(8′) is amoiety derived from the reaction of R⁸ with a moiety reactive with R⁸;each R¹⁰ is independently selected from C₁₋₃ alkanediyl, and substitutedC₁₋₃ alkanediyl, wherein the one or more substituent groups is —OH. Incertain embodiments, each R⁸ comprises a reactive functional group, andin certain embodiments, is —CH═CH₂. In certain embodiments, a terminalbis(sulfonyl)alkanol group is a1-(ethylenesulfonyl)-n-(vinylsulfonyl)alkanol group such as1-(ethylenesulfonyl)-3-(vinylsulfonyl)propan-2-ol, i.e.,—CH₂—CH₂—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—CH═CH₂. In certain embodiments, aterminal bis(sulfonyl)alkanol group has the structure—CH₂—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹—S(O)₂—CH═CH₂.

In certain embodiments, a bis(sulfonyl)alkanol group can also bedivalent such as when the group is incorporated into the backbone of aprepolymer such as the polythioethers disclosed herein. In certainembodiments, a divalent bis(sulfonyl)alkanol group can have the generalstructure —R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)—; in certainembodiments, —CH—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH₂—CH₂—, in certainembodiments, —R^(8′)—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—R^(8′)—, and in certainembodiments, —CH₂—CH₂—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—CH₂—CH₂—, where R^(8′)and R¹⁰ are as defined herein. In certain embodiments of abis(sulfonyl)alkanol, each R⁸ is an alkenyl group, each R^(8′) is anethane-diyl group and/or each R¹⁰ is methane-diyl.

A “bis(sulfonyl)alkanol” refers to a compound of the general formulaR⁸—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R⁸ where each R⁸ is a moiety having alreactive functional group; and each R¹⁰ is independently selected fromC₁₋₃ alkanediyl and substituted C₁₋₃ alkanediyl, wherein the one or moresubstituent groups is —OH. In certain embodiments, each R⁸ comprises aterminal group reactive with a thiol group such as, for example, analkenyl group, an epoxy group, a Michael acceptor group, or a groupcomprising a saturated carbon bearing a leaving group that are wellsuited for nucleophilic substitution such as, for example, —Cl, —Br, —I,—OSO₂CH₃ (mesylate), —OSO₂—C₆H₄—CH₃ (tosylate), etc. In certainembodiments, a bis(sulfonyl)alkanol may be a bis(vinylsulfonyl)alkanolcomprising terminal alkenyl groups. In certain embodiments abis(sulfonyl)alkanol may be a bis(vinylsulfonyl)alkanol in which R⁸comprises a terminal alkenyl group, such as a compound having theformula CH₂═CH—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH═CH₂. In certainembodiments, a bis(vinylsulfonyl)alkanol is1,3-bis(vinylsulfonyl)-2-propanol. In certain embodiments, abis(sulfonyl)alkanol containing compound can be prepared by reacting abis(vinylsulfonyl)alkanol with a compound having a reactive terminalfunctional group and a terminal group reactive with the terminal alkenylgroups of the bis(vinylsulfonyl)alkanol such as a thiol group or anepoxy group. In such embodiments, the bis(sulfonyl)alkanol can have thestructure R^(8′)—CH₂—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH₂—CH₂—R^(8′)where each R^(8′) is a moiety derived from the reaction of the compoundwith the terminal alkenyl groups of the bis(vinylsulfonyl)alkanol.

A “bis(sulfonyl)alkanol-containing” polymer, prepolymer, or adductrefers to polymer, prepolymer, or adduct in which one or more divalentbis(sulfonyl)alkanol groups are incorporated into the backbone of thepolymer, prepolymer, or adduct.

A divalent bis(sulfonyl)alkanol group can be incorporated in aprepolymer by reacting, for example, in a suitable ratio, a polythiolmonomer or prepolymer of Formula (3a) with a bis(sulfonyl)alkanol ofFormula (4a):R(—SH)_(w)  (3a)R⁸—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R⁸  (4a)where R is an organic moiety, w is an integer of at least 2 and each R⁸comprises a terminal group that is reactive with a thiol group such as,for example, an alkenyl group, and epoxy group, a Michael acceptorgroup, or a group comprising a saturated carbon bearing a leaving groupthat are well suited for nucleophilic substitution such as, for example,—Cl, —Br, —I, —OSO₂CH₃ (mesylate), —OSO₂—C₆H₄—CH₃ (tosylate), etc. Incertain embodiments, a bis(sulfonyl)alkanol of Formula (4a) may be abis(vinylsulfonyl)alkanol having the structure of Formula (4b):CH₂═CH—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH═CH₂  (4b)where each R¹⁰ is independently selected from C₁₋₃ alkanediyl andsubstituted C₁₋₃ alkanediyl, wherein the one or more substituent groupsis —OH. In certain embodiments, a bis(sulfonyl)alkanol may be1,3-bis(vinylsulfonyl)-2-propanol. Alternatively, a bis(sulfonyl)alkanolgroup can be incorporated into a prepolymer backbone by reacting, in asuitable ratio, a thiol-terminated bis(sulfonyl)alkanol of Formula (4c)with a reactant of Formula (3b):HS—R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)—SH  (4c)R(—R⁷)_(w)  (3b)where R is an organic moiety, w is an integer of at least 2, R^(8′) is amoiety derived from the reaction of R⁸ with a moiety reactive with R⁸;each R¹⁰ is as defined herein, and each R⁷ comprises a terminal groupthat is reactive with a thiol group such as, for example, an alkenylgroup, an epoxy group, a Michael acceptor group, or a group consistingof a saturated carbon bearing a leaving group that are well known fornucleophilic substitution such as, for example, —Cl, —Br, —I, —OSO₂CH₃(mesylate), —OSO₂—C₆H₄—CH₃ (tosylate), etc.

By choosing the appropriate ratio of the reactants of Formula (3a) andFormula (4a), or Formula (4c) and Formula (3b), one or morebis(sulfonyl)alkanol groups can be incorporated into a prepolymer aseither a chain segment, as part of a terminal bearing a reactive group,or both. For example, bis(vinylsulfonyl)alkanol can be used to introduceone or more 1,n-bis(ethylenesulfonyl)alkanol groups into the backbone ofa prepolymer, one or more terminal1-(ethylenesulfonyl)-n-(vinylsulfonyl)alkanol groups, or both.

In certain embodiments, bis(vinylsulfonyl)-2-propanol can be reactedwith thiol-terminated monomers/polymers to incorporate1,3-bis(ethylenesulfonyl)-2-propanol groups into a prepolymer backbone.

In certain embodiments, bis(vinylsulfonyl)-2-propanol can be reactedwith thiol-terminated monomers/polymers to provide1-(ethylenesulfonyl)-3-(vinylsulfonyl)-2-propanol terminal groups, wherethe terminal alkenyl group is a well-recognized Michael acceptor.

A moiety derived from the reaction of a bis(sulfonyl)alkanol with athiol group refers to the reaction product of a thiol group and a moietycontaining a terminal group reactive with the thiol group. Examples ofterminal groups reactive with thiol groups include epoxy groups,ethylene groups, and Michael acceptor groups. In certain embodiments, amoiety derived from the reaction of a bis(sulfonyl)alkanol with a thiolgroup has the structure: —CH₂—CH₂—R—, —CH(—OH)—CH₂—R—, —CH₂—CH(—OH)—R—,or —CH₂—CH₂—SO₂—R—, where R refers to a covalent bond or to an organicmoiety bonded to a sulfonyl group.

A moiety derived from the reaction of a bis(sulfonyl)alkanol with athiol group also refers to a moiety R^(8′), which is derived from thereaction of group R⁸ with a thiol group, where R⁸ comprises a terminalgroup reactive with a thiol group.

In certain embodiments, R^(8′) is derived from the reaction of abis(sulfonyl)alkanol with a compound having a terminal group reactivewith a thiol group and a group reactive with a bis(sulfonyl)alkanol. Incertain embodiments R^(8′) is derived from the reaction of abis(ethylenesulfonyl)alkanol with a compound having a terminal groupreactive with a thiol group and a group reactive with an ethylene group.In such embodiment, R^(8′) may have the structure: —CH₂—CH₂—R′—CH₂—CH₂—,—CH(—OH)—CH₂—R′—CH₂—CH₂—, —CH₂—CH(—OH)—R¹—CH₂—CH₂—, or—CH₂—CH₂—SO₂—R′—CH₂—CH₂—, where R′ is an organic moiety derived from thereaction of the compound used to cap the bis(ethylenesulfonyl)alkanolwith a functional group such as an ethylene group, an epoxy group, aMichael acceptor group, or a group comprising a saturated carbon bearinga leaving group that are well suited for nucleophilic substitution suchas, for example, —Cl, —Br, —I, —OSO₂CH₃ (mesylate), —OSO₂—C₆H₄—CH₃(tosylate), etc.

In certain embodiments, R^(8′) is selected from C₂₋₁₀ alkanediyl,substituted C₂₋₁₀ alkanediyl, C₂₋₁₀ heteroalkanediyl, substituted C₂₋₁₀heteroalkanediyl, C₄₋₁₄ alkanecycloalkanediyl, substituted C₄₋₁₄alkanecycloalkanediyl, C₄₋₁₄ heteroalkanecycloalkanediyl, substitutedC₄₋₁₄ heteroalkanecycloalkanediyl, C₄₋₁₄ alkanearenediyl, substitutedC₄₋₁₄ alkanearenediyl, C₄₋₁₄ heteroalkanearenediyl, and substitutedC₄₋₁₄ heteroalkanearenediyl. In certain embodiments, R^(8′) isethane-diyl.

In certain embodiments, R⁸ is selected from C₂₋₁₀ alkyl, substitutedC₂₋₁₀ alkyl, C₂₋₁₀ heteroalkyl, substituted C₂₋₁₀ heteroalkyl, C₄₋₁₄alkanecycloalkyl, substituted C₄₋₁₄ alkanecycloalkyl, C₄₋₁₄heteroalkanecycloalkyl, substituted C₄₋₁₄ heteroalkanecycloalkyl, C₄₋₁₄alkanearyl, substituted C₄₋₁₄ alkanearyl, C₄₋₁₄ heteroalkanearyl, andsubstituted C₄₋₁₄ heteroalkanearyl. In certain embodiments, R⁸ isethylene, i.e., —CH═CH₂.

“Cycloalkanediyl” refers to a diradical saturated monocyclic orpolycyclic hydrocarbon group. In certain embodiments, thecycloalkanediyl group is C₃₋₁₂ cycloalkanediyl, C₃₋₈ cycloalkanediyl,C₃₋₆ cycloalkanediyl, and in certain embodiments, C₅₋₆ cycloalkanediyl.Examples of cycloalkanediyl groups include cyclohexane-1,4-diyl,cyclohexane-1,3-diyl, and cyclohexane-1,2-diyl.

“Cycloalkyl” refers to a saturated monocyclic or polycyclic hydrocarbonmonoradical group. In certain embodiments, the cycloalkyl group is C₃₋₁₂cycloalkyl, C₃₋₈ cycloalkyl, C₃₋₆ cycloalkyl, and in certainembodiments, C₅₋₆ cycloalkyl.

“Heteroalkanediyl” refers to an alkanediyl group in which one or more ofthe carbon atoms are replaced with a heteroatom, such as N, O, S, or P.In certain embodiments of heteroalkanediyl, a heteroatom is selectedfrom N and O.

“Heteroalkanearenediyl” refers to an alkanearenediyl group in which oneor more of the carbon atoms are replaced with a heteroatom, such as N,O, S, or P. In certain embodiments of heteroalkanearenediyl, theheteroatom is selected from N and O.

“Heterocycloalkanediyl” refers to a cycloalkanediyl group in which oneor more of the carbon atoms are replaced with a heteroatom, such as N,O, S, or P. In certain embodiments of heterocycloalkanediyl, theheteroatom is selected from N and O.

“Michael acceptor” refers to substituted alkene/alkyne compounds inwhich at least one alkene/alkyne group is directly attached to one ormore electron-withdrawing groups such as carbonyl (—CO), nitro (—NO₂),nitrile (—CN), alkoxycarbonyl (—COOR), phosphonate (—PO(OR)₂),trifluoromethyl (—CF₃), sulfonyl (—SO₂—), trifluormethanesulfonyl(—SO₂CF₃), p-toluenesulfonyl (—SO₂—C₆H₄—CH₃), etc. Types of compoundsthat function as Michael acceptor are vinyl ketones, quinones,nitroalkenes, acrylonitriles, acrylates, methacrylates, cyanoacrylates,acrylamides, maleimides, dialkyl vinylphosphonate and vinylsulfones.Other examples of Michael acceptors are disclosed in Mather et al.,Prog. Polym. Sci. 2006, 31, 487-531. Michael acceptor compounds havingmore than one Michael acceptor group are also well known. Examplesinclude diacrylates such as ethylene glycol diacrylate and diethyleneglycol diacrylate, dimethacrylates such as ethylene glycol methacrylateand diethylene glycol methacrylate, bismaleimides such asN,N′-(1,3-phenylene)dimaleimide and1,1′-(methylenedi-4,1-phenylene)bismaleimide, vinylsulfones such asdivinyl sulfone and 1,3-bis(vinylsulfonyl)-2-propanol, etc. In certainembodiments, a Michael acceptor group has the structure of Formula (7a)or Formula (7b):—CH₂—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH═CH₂  (7a)—CH₂—CH₂—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—CH═CH₂  (7b)where each R¹⁰ is independently selected from C₁₋₃ alkanediyl andsubstituted C₁₋₃ alkanediyl, wherein the one or more substituent groupsis —OH.

A “Michael acceptor compound” refers to a compound comprising at leastone terminal Michael acceptor group. In certain embodiments, a Michaelacceptor compound is divinyl sulfone, and a Michael acceptor group isvinylsulfonyl, i.e., —S(O)₂—CH═CH₂. In certain embodiments, a Michaelacceptor compound is a bis(vinylsulfonyl)alkanol, and a Michael acceptorgroup is 1-(ethylenesulfonyl)-n-(vinylsulfonyl)alkanol(—CH₂—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH═CH₂), and in certainembodiments, 1-(ethylenesulfonyl)-3-(vinylsulfonyl)propan-2-ol(—CH₂—CH₂—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—CH═CH₂).

Hydroxypyridinones comprise groups such as 3-hydroxy-4-pyridinone and3-hydroxy-2-pyridinone having the structure of Formula (8a) or Formula(8b), respectively:

where R is an organic groups such as an alkyl group. A metal chelatingagent derived from a hydroxypyridinone comprises a hydroxypyridinonegroup and one or more reactive functional groups such as terminal thiolgroups.

A “metal ligand” refers to an ion or molecule that binds to a metal atomand potentially other atoms to form a coordination complex. The bondingbetween the metal and or atoms generally involves donation of one ormore electronic pairs to the metal and the nature of the bonding can becovalent or ionic. Metal ligands provided by the present disclosure arecapable of forming coordination complexes to aerospace surfaces such asaluminum and titanium surfaces, which may be oxidized. In the case ofoxidized surfaces a metal ligand may form a coordination complex with ametal such as Al(III) and oxygen atoms. The coordination complex canenhance the adhesion to the metal or oxidized metal surface.

Metal ligands may be incorporated into the backbone of a prepolymer asprovided by the present disclosure. In addition to a moiety capable offorming a coordination complex, for incorporation into a prepolymerbackbone, the metal ligand will comprise, or will be derivatized tocomprise at least two groups that are reactive with a group of a subunitof a prepolymer. Such reactive metal ligands may be commerciallyavailable or may be derivatized to include appropriate reactivesubstituent groups using methods known to those skilled in the ar.

A “polyalkoxysilyl group” refers to a group having the formula:—Si(—R⁴)_(p)(—OR⁴)_(3-p)  (9)where p is selected from 0, 1, and 2; and each R⁴ is independentlyselected from C₁₋₄ alkyl. In certain embodiments of a polyalkoxysilylgroup, p is 0, p is 1, and in certain embodiments, p is 2. In certainembodiments of a polyalkoxysilyl group, each R⁴ is independentlyselected from ethyl and methyl. In certain embodiments of apolyalkoxysilyl group, each R⁴ is ethyl, and in certain embodiments,each R⁴ is methyl. In certain embodiments of a polyalkoxysilyl group,the group is selected from —Si(—OCH₂CH₃)₃, —Si(—OCH₃)₃,—Si(—CH₃)(—OCH₃)₂, —Si(—CH₃)₂(—OCH₃), —Si(—CH₃)(—OCH₂CH₃)₂,—Si(—CH₃)₂(—OCH₂CH₃), —Si(—CH₂CH₃)(—OCH₃), and —Si(—CH₂CH₃)₂(—OCH₃).

“Substituted” refers to a group in which one or more hydrogen atoms areeach independently replaced with the same or different substituent(s).In certain embodiments, a substituent is selected from halogen,—S(O)₂OH, —S(O)₂, —SH, —SR where R is C₁₋₆ alkyl, —COOH, —NO₂, —NR₂where each R is independently selected from hydrogen and C₁₋₃ alkyl,—CN, —C═O, C₁₋₆ alkyl, —CF₃, —OH, phenyl, C₂₋₆ heteroalkyl, C₅₋₆heteroaryl, C₁₋₆ alkoxy, and —COR where R is C₁₋₆ alkyl. In certainembodiments, a substituent is chosen from —OH, —NH₂, and C₁₋₃ alkyl.

As used herein, “polymer” refers to oligomers, homopolymers, andcopolymers. Unless stated otherwise, molecular weights are numberaverage molecular weights for polymeric materials indicated as “M_(n)”as determined, for example, by gel permeation chromatography using apolystyrene standard in an art-recognized manner.

Reference is now made to certain embodiments of metal ligand-containingprepolymers such as metal ligand-containing polythioethers, compositionsthereof, and methods of synthesis. The disclosed embodiments are notintended to be limiting of the claims. To the contrary, the claims areintended to cover all alternatives, modifications, and equivalents.

To enhance the tensile strength and the adhesion of cured aerospacesealants to surfaces, such as bare or anodized metal surfaces, metalligands such as bis(sulfonyl)alkanols are incorporated into the backboneof sulfur-containing prepolymers. Metal ligand-containing prepolymerssuch as bis(sulfonyl)alkanol-containing sulfur-containing prepolymerscan be adapted for any suitable curing chemistry. For example,thiol-terminated metal ligand-containing polythioether prepolymers andpolyepoxy curing agents provide sealants useful for aerospaceapplications.

Bis(Sulfonyl)Alkanol-Containing Polythioethers

Bis(sulfonyl)alkanol-containing polythioethers provided by the presentdisclosure are characterized by having one or more bis(sulfonyl)alkanolgroups incorporated into the backbone of the polythioether.

Polythioethers useful in aerospace sealant applications are disclosed,for example, in U.S. Pat. No. 6,172,179. Polythioethers refer tocompounds comprising at least two thioether, —C—S—C— linkages.Polythioethers may be prepared, for example, by reacting dithiols withdivinyl ethers. In general, bis(sulfonyl)alkanol-containingpolythioethers may be prepared by reacting a monomericbis(sulfonyl)alkanol having terminal groups reactive with terminal of apolythioether.

In certain embodiments, a bis(sulfonyl)alkanol-containing polythioethercomprises a moiety of Formula (10):—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—  (10)wherein each R¹⁰ is independently selected from a C₁₋₃ alkanediyl andsubstituted C₁₋₃ alkanediyl, wherein one or more substituent groups is—OH.

In certain embodiments, bis(sulfonyl)alkanol-containing polythioetherscomprise the structure of Formula (11):-A-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-  (11)wherein:

each R^(8′) is a moiety derived from the reaction of abis(sulfonyl)alkanol with thiol groups;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH; and

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

wherein:

-   -   each R¹ is independently selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NR⁵—,            wherein R⁵ is selected from hydrogen and methyl; and    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and    -   p is an integer from 2 to 6.

In certain embodiments of Formula (11) and Formula (12), each R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)— wherein each X is independentlyselected from —O— and —S—. In certain embodiments wherein R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, each X is —O— and in certainembodiments, each X is —S—. In certain embodiments, each R³ is hydrogen.

In certain embodiments of Formula (11) and Formula (12), each R¹ is—[—(CH₂)_(s)—X—]_(q)—(CH₂)_(r)— wherein each X is independently selectedfrom —O— and —S—. In certain embodiments wherein R¹ is—[—(CH₂)_(s)—X—]—(CH₂)_(r)—, each X is —O— and in certain embodiments,each X is —S—.

In certain embodiments of Formula (11) and Formula (12), each R¹ is—[—(CH₂—)_(s)—X—]_(q)—(CH₂)_(r)—, where s is 2, X is O, q is 2, r is 2,R² is ethanediyl, m is 2, and n is 9.

In certain embodiments of Formula (11) and Formula (12), each R¹ isderived from dimercaptodioxaoctane (DMDO) and in certain embodiments,each R¹ is derived from dimercaptodiethylsulfide (DMDS).

In certain embodiments of Formula (11) and Formula (12), each m isindependently an integer from 1 to 3. In certain embodiments, each m isthe same and is 1, 2, and in certain embodiments, 3.

In certain embodiments of Formula (11) and Formula (12), n is an integerfrom 1 to 30, an integer from 1 to 20, an integer from 1 to 10, and incertain embodiments, and an integer from 1 to 5. In addition, in certainembodiments, n may be any integer from 1 to 60.

In certain embodiments of Formula (11) and Formula (12), each p isindependently selected from 2, 3, 4, 5, and 6. In certain embodiments,each p is the same and is 2, 3, 4, 5, or 6.

In Formula (11), each R^(8′) is a group derived from the reaction of athiol group and a group reactive with a thiol group such as a terminalalkenyl group, a terminal epoxy group, or a terminal Michael acceptorgroup. In certain embodiments of Formula (11) and Formula (12), eachR^(8′) is independently selected from C₂₋₁₀ alkanediyl, substitutedC₂₋₁₀ alkanediyl, C₂₋₁₀ heteroalkanediyl, substituted C₄₋₁₀heteroalkanediyl, C₄₋₁₄ alkanecycloalkanediyl, substituted C₄₋₁₄alkanecycloalkanediyl, C₄₋₁₄ heteroalkanecycloalkanediyl, substitutedC₄₋₁₄ heteroalkanecycloalkanediyl, C₂₋₁₄ alkanearenediyl, substitutedC₄₋₁₄ alkanearenediyl, C₄₋₁₄ heteroalkanearenediyl, and substitutedC₄₋₁₄ heteroalkanearenediyl. In certain embodiments, each R^(8′) is thesame. In certain embodiments, each R^(8′) is ethane-diyl, i.e.,—CH₂—CH₂—.

In certain embodiments of Formula (11), each R¹⁰ is independentlyselected from methane-diyl, ethane-diyl, and 1,3-propane-diyl. Incertain embodiments, each R¹⁰ is methane-diyl, in certain embodiments,ethane-diyl, and in certain embodiments, 1,3-propane-diyl.

In certain embodiments of Formula (11), each R^(8′) is ethane-diyl andeach R¹⁰ is methane-diyl.

In certain embodiments, a bis(sulfonyl)alkanol-containing polythioetheris selected from a bis(sulfonyl)alkanol-containing polythioether ofFormula (13a), a bis(sulfonyl)alkanol-containing polythioether ofFormula (13b), and a combination thereof:R⁶-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)—R⁶  (13a){R⁶-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)-V′—}_(z)B  (13b)wherein,

N is an integer from 1 to 10;

each R^(8′) is a moiety derived from the reaction of abis(sulfonyl)alkanol with thiol groups;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NR⁵—,            wherein R⁵ is selected from hydrogen and methyl;    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and    -   p is an integer from 2 to 6;

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6; and    -   each V is a group comprising a terminal group reactive with a        thiol group; and

each —V′— is derived from the reaction of —V with a thiol; and

each R⁶ is independently selected from hydrogen and a moiety having aterminal reactive group.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), N is 1, 2, 3, 4, 5, 6, 7, 8, 9, andin certain embodiments N is 10. In certain embodiments ofbis(sulfonyl)alkanol-containing polymers of Formula (13a) and Formula(13b), the molecular weight is from 400 Daltons to 20,000 Daltons. Incertain embodiments, bis(sulfonyl)alkanol-containing polythioethers ofFormula (13a) comprise a combination of bis(sulfonyl)alkanol-containingpolythioethers of Formula (13a) with different values for N. In certainembodiments, bis(sulfonyl)alkanol-containing polythioethers of Formula(13b) comprise a combination of bis(sulfonyl)alkanol-containingpolythioethers of Formula (13b) with different values for N. In certainembodiments of bis(sulfonyl)alkanol-containing polythioethers of Formula(13a) and Formula (13b), N is 1.

In certain embodiments of Formula (13a) and Formula (13b), each R^(8′)is a group derived from the reaction of a thiol group and a groupreactive with a thiol group such as a terminal alkenyl group, a terminalepoxy group, or a terminal Michael acceptor group. In certainembodiments of Formula (13a) and Formula (13b), each R^(8′) isindependently selected from C₂₋₁₀ alkanediyl, substituted C₂₋₁₀alkanediyl, C₂₋₁₀ heteroalkanediyl, substituted C₂₋₁₀ heteroalkanediyl,C₄₋₁₄ alkanecycloalkanediyl, substituted C₄₋₁₄ alkanecycloalkanediyl,C₄₋₁₄ heteroalkanecycloalkanediyl, substituted C₄₋₁₄heteroalkanecycloalkanediyl, C₄₋₁₄ alkanearenediyl, substituted C₄₋₁₄alkanearenediyl, C₄₋₁₄ heteroalkanearenediyl, and substituted C₄₋₁₄heteroalkanearenediyl. In certain embodiments, each R^(8′) is the same.In certain embodiments, each R^(8′) is ethane-diyl, i.e., —CH₂—CH₂—.

In certain embodiments of Formula (13a) and Formula (13b), each R¹⁰ isindependently selected from methane-diyl, ethane-diyl, and1,3-propane-diyl. In certain embodiments, each R¹⁰ is methane-diyl, incertain embodiments, ethane-diyl, and in certain embodiments,1,3-propane-diyl.

In certain embodiments of Formula (13a) and Formula (13b), each R^(8′)is ethane-diyl and each R¹⁰ is methane-diyl.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)— wherein each X is independentlyselected from —O— and —S—. In certain embodiments wherein R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, each X is —O— and in certainembodiments, each X is —S—. In certain embodiments, each R³ is hydrogen.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is—[—(CH₂)_(s)—X—]_(q)—(CH₂)_(r)— wherein each X is independently selectedfrom —O— and —S—. In certain embodiments wherein R¹ is—[—(CH₂)_(s)—X—]_(q)—(CH₂)_(r)—, each X is —O— and in certainembodiments, each X is —S—.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is—[—(CH₂—)_(s)—X—]_(q)—(CH₂)_(r)—, where s is 2, X is O, q is 2, r is 2,R² is ethanediyl, m is 2, and n is 9.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is derived from DMDO and incertain embodiments, each R¹ is derived from DMDS.

In certain embodiments, each m is independently an integer from 1 to 3.In certain embodiments, each m is the same and is 1, 2, and in certainembodiments, 3.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), n is an integer from 1 to 30, aninteger from 1 to 20, an integer from 1 to 10, and in certainembodiments, and integer from 1 to 5. In addition, in certainembodiments, n may be any integer from 1 to 60.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each p is independently selectedfrom 2, 3, 4, 5, and 6. In certain embodiments, each p is the same andis 2, 3, 4, 5, or 6.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is—[(CH₂—)_(s)—X—]_(q)—(CH₂)_(r)—, where s is 2, X is —O—, q is 2, r is 2,R² is ethanediyl, m is 2, and n is 9.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is selected from C₂₋₆alkanediyl and —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, and in certain embodiments X is —O—and in certain embodiments, X is —S—.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), where R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, s is 2, r is 2, q is 1, and X is —S—;in certain embodiments, wherein s is 2, q is 2, r is 2, and X is —O—;and in certain embodiments, s is 2, r is 2, q is 1, and X is —O—.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), where R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, each R³ is hydrogen, and in certainembodiments, at least one R³ is methyl.

In certain embodiment of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R¹ is the same, and in certainembodiments, at least one R¹ is different.

In certain embodiment of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R⁶ is the same and the terminalreactive group is selected from —SH, —CH═CH₂, —NH₂, —OH, an epoxy group,a polyalkoxysilyl group, and a Michael acceptor group.

In certain embodiments, a bis(sulfonyl)alkanol-containing polythioetherof Formula (13a) has the structure of Formula (14):R¹¹—R^(8′)—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—R^(8′)—R¹¹  (14)wherein each R^(8′) is as defined herein; each R¹¹ isH—[—S—(—R¹²—O—)₂—R¹²—S—(—R¹²—O—)₃—R¹²—]₂—S—(—R¹²—O—)₂—R¹²—S—, whereineach R¹² is —CH₂—CH₂—.

In certain embodiments, a bis(sulfonyl)alkanol-containing polythioetherof Formula (13a) has the structure of Formula (15):R¹¹—CH₂CH₂—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—CH₂CH₂—R¹¹  (15)wherein each R¹¹ isH—[—S—(—R¹²—O—)₂—R¹²—S—(—R¹²—O—)₃—R²—]₂—S—(—R¹²—O—)₂—R¹²—S—, whereineach R¹² is —CH₂—CH₂—.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), each R⁶ is hydrogen, and thebis(sulfonyl)alkanol-containing polythioethers are thiol-terminated,having the structures of Formula (16a), Formula (16b), Formula (16c), orFormula (16d):H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)-H  (16a){H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)-V′—}_(z)B  (16b)H-A-[-CH₂—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH₂—CH₂-A-]_(N)-H  (16c){H-A-[-CH₂—CH₂—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH₂—CH₂-A-]_(N)-V′—}_(z)B  (16d)where A, N, R^(8′), R¹⁰, V′, z, and B are defined herein.

B(—V)_(z) represents a polyfunctionalizing agent. Thepolyfunctionalizing agent may be a single type of polyfunctionalizingagent or a combination of different polyfunctionalizing agents, whichmay have the same or different functionalities. In certain embodiments,z is 3, 4, 5, or 6. Suitable polyfunctionalizing agents includetrifunctionalizing agents, that is, compounds where z is 3. Suitabletrifunctionalizing agents include, for example, triallyl cyanurate(TAC), modified-1,2,3-propanetrithiol, modified-isocyanurate-containingtrithiols, 1,2,4-trivinylcyclohexane, and combinations of any of theforegoing, as disclosed, for example, in U.S. Application PublicationNo. 2010/0010133 at paragraphs [0102]-[0105], the cited portion of whichis incorporated by reference. Other useful polyfunctionalizing agentsinclude trimethylolpropane trivinyl ether. Mixtures ofpolyfunctionalizing agents may also be used. Suitableisocyanurate-containing functionalizing agents are disclosed, forexample, in U.S. Application Publication No. 2011/0319559.

R⁶ represents a moiety having a terminal reactive group. The terminalreactive group can be selected as suitable for a particular curingchemistry. For example, in certain embodiments, each R⁶ is the same andthe reactive group is selected from —SH, —CH═CH₂, —NH₂, —OH, an epoxygroup, polyalkoxysilyl group, and a Michael acceptor group. The use of aparticular curing chemistry can be chosen to obtain a desired, forexample, the curing time of a composition, the application method,surface compatibility, shelf life, pot life, and/or the properties ofthe cured sealant composition. For example, in certain embodiments, abis(sulfonyl)alkanol-containing polythioether of Formula (13a) and/orFormula (13b) is thiol-terminated and R⁶ is hydrogen or a moietyterminated in a thiol group. In certain embodiments, B(—V)_(z) is analkenyl-terminated polyfunctionalizing agent, where each —V comprises aterminal alkenyl group, and accordingly, each —V′— represents a moietyformed by the reaction of an alkenyl group and a group reactive withalkenyl groups.

In certain embodiments, a polyfunctionalizing agent may include one ormore bis(sulfonyl)alkanol groups. For example, in certain embodiments, apolyfunctionalizing agent may be reacted with a bis(sulfonyl)alkanolhaving a terminal group reactive with a terminal group of thepolyfunctionalizing agent and a terminal group reactive with a thiolgroup. Thus, in certain embodiments, a bis(sulfonyl)alkanol-containingpolyfunctionalizing agent of Formula (17) may be formed by reacting abis(sulfonyl)alkanol of Formula (4a) with a polyfunctionalizing agent ofhaving the formula B(—V)_(z):{R⁸—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)—V′—}_(z)B  (17)where R⁸, R^(8′), R¹⁰, B and V′ are defined herein.

In certain embodiments of bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b), R⁶ is hydrogen and thebis(sulfonyl)alkanol-containing polythioethers of Formula (13a) andFormula (13b) are thiol-terminated.

In certain embodiments, bis(sulfonyl)alkanol-containing polythioethersof Formula (13a) and Formula (13b) are thiol-terminated, e.g., each R⁶is hydrogen, and can be referred to as an uncappedbis(sulfonyl)alkanol-containing polythioether. In certain embodiments,an uncapped bis(sulfonyl)alkanol-containing polythioether is a liquid atroom temperature. Moreover, in certain embodiments, an uncappedbis(sulfonyl)alkanol-containing polythioether has a viscosity, at 100%solids, of less than 500 poise, such as 100 poise to 300 poise or, insome cases, 100 poise to 200 poise at a temperature of about 25° C. anda pressure of about 760 mm Hg, determined according to ASTM D-2849§79-90 and measured using a Brookfield CAP 2000 viscometer. Any endpointwithin the foregoing ranges can also be used. In certain embodiments, anuncapped bis(sulfonyl)alkanol-containing polythioether has a numberaverage molecular weight of 400 grams per mole to 10,000 grams per mole,such as 1,000 grams per mole to 8,000 grams per mole, the molecularweight being determined, for example, by gel permeation chromatographyusing a polystyrene standard. Any endpoints within the foregoing rangescan also be used. In certain embodiments, the T_(g) of an uncappedbis(sulfonyl)alkanol-containing polythioether is not higher than −55°C., such as not higher than −60° C.

In certain embodiments, a bis(sulfonyl)alkanol-containing polythioethermay be capped or terminated with a particular reactive group to adaptthe bis(sulfonyl)alkanol-containing polythioether for use with differentcuring chemistries.

Bis(sulfonyl)alkanol-containing polythioethers of Formula (13a) andFormula (13b) in which R⁶ is a moiety having a terminal reactive groupmay be prepared by capping the corresponding thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (13a) andFormula (13b) wherein each R⁶ is hydrogen with a moiety having aterminal reactive group and a group reactive with a thiol group. Cappedanalogs of polythioethers and methods of preparing capped analogs ofpolythioethers useful in aerospace sealant applications are disclosed,for example, in U.S. Pat. No. 6,172,179 and in U.S. ApplicationPublication No. 2011/0319559, each of which is incorporated byreference. In certain embodiments, R⁶ comprises a terminal alkenylgroup, a terminal epoxy group, a terminal polyalkoxysilyl group, aterminal amine group, or a terminal Michael acceptor group. A cappinggroup R⁶ may have a molecular weight less than 500 Daltons.

Terminal-modified bis(sulfonyl)alkanol-containing polythioethersprovided by the present disclosure may be prepared by a number ofmethods known to those skilled in the art. For example, to obtainterminal-modified bis(sulfonyl)alkanol-containing polythioether ofFormula (13a) and Formula (13b), a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (16a) orFormula (16b) as disclosed herein, may be reacted with a compound havinga terminal functional group and a terminal group reactive with thiolgroups.

For example, to obtain an alkenyl-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (13a), athiol-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (16a) may be reacted with a compound containing a terminalalkenyl group and an isocyanate group such as a group derived from TMI,2-isocyanatoethyl methacrylate, or allyl isocyanate, in the presence ofdibutyltin dilaurate catalyst. As a further example, abis(sulfonyl)alkanol-containing polythioether of Formula (13a) may bereacted with an alkene-ol such as 3-butene-1-ol and an aldehyde such asformaldehyde in the presence of a sulfonic acid (e.g., 4.7 meq/g H⁺)such as Amberlyst™ 15 in an organic solvent such as toluene to providean alkenyl-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (13a). In certain embodiments, an alkenyl-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (13a) may beprepared by reacting a polyalkenyl compound such as a dialkenyl compoundwith a thiol-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (16a).

Polyalkoxysilyl-terminated bis(sulfonyl)alkanol-containingpolythioethers of Formula (13a) may be prepared, for example, byreacting a thiol-terminated bis(sulfonyl)alkanol-containingpolythioether of Formula (16a) with a polyalkoxysilane such as a3-isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltriethoxysilanein the presence of dibutyltin dilaurate to provide the correspondingpolyalkoxysilyl-terminated bis(sulfonyl)alkanol-containingpolythioethers of Formula (13a). In certain embodiments, apolyalkoxysilyl-terminated bis(sulfonyl)alkanol-containing polythioetherof Formula (13a) may be prepared by reacting a vinyl alkoxysilane with athiol-terminated bis(sulfonyl)alkanol-containing polythioether.

Epoxy-terminated bis(sulfonyl)alkanol-containing polythioethers ofFormula (13a) may be prepared, for example, by reacting thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (16a) with amonoepoxide such as epichlorohydrin, or with an alkenyl glycidylcompound such as allyl glycidyl ether to provide the correspondingepoxy-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (13a).

Amine-terminated bis(sulfonyl)alkanol-containing polythioethers ofFormula (13a) may be prepared, for example, by reacting an activatedalkenyl-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (13a) or a Michael acceptor-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (13a) withdiamine an amino-substituted aniline such as 4-(aminomethyl)aniline, oran alkylamine such as n-butylamine, optionally in the presence of acatalyst such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in an organicsolvent to provide the corresponding amine-terminatedbis(sulfonyl)alkanol-containing polythioethers of Formula (13a).Alternatively, amine-terminated bis(sulfonyl)alkanol-containingpolythioethers of Formula (13a) may be obtained by reacting anisocyanate-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (13a) with a diamine such as 4-(aminomethyl)aniline to providethe corresponding amine-terminated bis(sulfonyl)alkanol-containingpolythioether of Formula (13a). Amine-terminatedbis(sulfonyl)alkanol-containing polythioethers of Formula (13a) may alsobe obtained by reacting a hydroxyl-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (13a) with anamino-substituted benzoate such as ethyl-4-aminobenzoate in the presenceof Bu₂SnO or NaOMe at elevated temperature to provide the correspondingamine-terminated bis(sulfonyl)alkanol-containing polythioether ofFormula (13a).

Isocyanate-terminated bis(sulfonyl)alkanol-containing polythioethers ofFormula (13a) may be prepared, for example, by reacting athiol-terminated bis(sulfonyl)alkanol-containing polythioethers ofFormula (16a) with a diisocyanate such as TDI, Isonate™ 143L(polycarbodiimide-modified diphenylmethane diisocyanate), Desmodur®N3400 (1,3-diazetidine-2,4-dione, 1,3-bis(6-isocyanatohexyl)-), IPDI(isophorone diisocyanate), or Desmodur® W (H₁₂MDI) optionally in thepresence of a catalyst such as dibutyltin dilaurate.Isocyanate-terminated sulfur-containing polymers may be used asintermediates in the synthesis of other terminal-modifiedsulfur-containing polymers such as certain amine-terminated andthiol-terminated bis(sulfonyl)alkanol-containing polythioethers providedby the present disclosure.

Similar reactions may be used to prepare cappedbis(sulfonyl)alkanol-containing prepolymers of Formula (13b).

In certain embodiments, a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether comprises the reactionproduct of reactants comprising:

-   -   (a) a thiol-terminated polythioether selected from a        thiol-terminated polythioether of Formula (18a), a        thiol-terminated polythioether of Formula (18b), and a        combination thereof:        HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a)        {HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′-}_(z)B  (18b)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NR⁵—,            wherein R⁵ is selected from hydrogen and methyl;    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6; and    -   B represents a core of a z-valent polyfunctionalizing agent        B(—V)_(z) wherein:        -   z is an integer from 3 to 6; and        -   each V is a group comprising a terminal group reactive with            a thiol group; and        -   each —V′— is derived from the reaction of —V with a thiol;            and

(b) a bis(sulfonyl)alkanol of Formula (19):R⁸—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R⁸  (19)

wherein,

-   -   each R⁸ is independently selected from a moiety comprising a        terminal group reactive with a terminal thiol group; and    -   each R¹⁰ is independently selected from C₁₋₃ alkanediyl and        substituted C₁₋₃ alkanediyl, wherein one or more substituent        groups is —OH.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), each R¹ is —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—wherein each X is independently selected from —O— and —S—. In certainembodiments wherein R¹ is —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, each X is—O— and in certain embodiments, each X is —S—. In certain embodiments,each R³ is hydrogen.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), each R¹ is —[—(CH₂)_(s)—X—]_(q)—(CH₂)_(r)—wherein each X is independently selected from —O— and —S—. In certainembodiments wherein R¹ is —[—(CH₂)_(s)—X—]_(q)—(CH₂)_(r)—, each X is —O—and in certain embodiments, each X is —S—.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), each R¹ is —[—(CH₂—)_(p)—X—]_(q)—(CH₂)_(r)—,where s is 2, X is O, q is 2, r is 2, R² is ethanediyl, m is 2, and n is9.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), each R¹ is derived from DMDO and in certainembodiments, each R¹ is derived from DMDS.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), each m is independently an integer from 1 to 3.In certain embodiments, each m is the same and is 1, 2, and in certainembodiments, 3.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), n is an integer from 1 to 30, an integer from 1to 20, an integer from 1 to 10, and in certain embodiments, and integerfrom 1 to 5. In addition, in certain embodiments, n may be any integerfrom 1 to 60.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), each p is independently selected from 2, 3, 4,5, and 6. In certain embodiments, each p is the same and is 2, 3, 4, 5,or 6.

In certain embodiments of thiol-terminated polythioethers of Formula(18a) and Formula (18b), R¹ is derived from DMDO, R² is derived from adivinyl ether, and the polyfunctionalizing agent is TAC.

In certain embodiments, a polythioether prepolymer of Formula (18a) hasthe structure of Formula (20):H—[—S—(—CH₂CH₂—O—)₂—CH₂CH₂—S—(—CH₂CH₂—O—)₃—CH₂CH₂—]_(N)—S—(—CH₂CH₂—O—)₂—CH₂CH₂—SH  (20)

In certain embodiments of Formula (19), each R¹⁰ is independentlyselected from methane-diyl, ethane-diyl, and 1,3-propane-diyl. Incertain embodiments, each R¹⁰ is methane-diyl, in certain embodiments,ethane-diyl, and in certain embodiments, 1,3-propane-diyl.

In certain embodiments of Formula (19), R⁸ comprises a group reactivewith a thiol group selected from an alkenyl group, an epoxy group, and aMichael acceptor group. In certain embodiments, each R⁸ is terminatedwith an alkenyl group. In certain embodiments, R⁸ is selected from C₂₋₁₀alkyl, substituted C₂₋₁₀ alkyl, C₂₋₁₀ heteroalkyl, substituted C₂₋₁₀heteroalkyl, C₄₋₁₄ alkanecycloalkyl, substituted C₄₋₁₄ alkanecycloalkyl,C₄₋₁₄ heteroalkanecycloalkyl, substituted C₄₋₁₄ heteroalkanecycloalkyl,C₄₋₁₄ alkanearyl, substituted C₄₋₁₄ alkanearyl, C₄₋₁₄ heteroalkanearyl,and substituted C₄₋₁₄ heteroalkanearyl. In certain embodiments, R⁸ isethylene, i.e., —CH═CH₂.

In certain embodiments, a bis(sulfonyl)alkanol of Formula (19) comprisesa bis(vinylsulfonyl)alkanol. In certain embodiments, abis(vinylsulfonyl)alkanol has the structure of Formula (21):CH₂═CH—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—CH═CH₂  (21)where R¹⁰ is defined herein.

In certain embodiments, a bis(vinylsulfonyl)alkanol of Formula (19)comprises 1,3-bis(vinylsulfonyl)-2-propanol and has the structure ofFormula (22):CH₂═CH—S(O)₂—CH₂—CH(—OH)—CH₂—S(O)₂—CH═CH₂  (22).

Thiol-terminated polythioethers of Formula (18a) and Formula (18b) and abis(vinylsulfonyl)alkanol of Formula (19) may be reacted in the presenceof a base catalyst such as an amine catalyst. Examples of suitable aminecatalysts include, for example,triethylenediamine(1,4-diazabicyclo[2.2.2]octane, DABCO),dimethylcyclohexylamine (DMCHA), dimethylethanolamine (DMEA),bis-(2-dimethylaminoethyl)ether, N-ethylmorpholine, triethylamine,1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), pentamethyldiethylenetriamine(PMDETA), benzyldimethylamine (BDMA),N,N,N′-trimethyl-N′-hydroxyethyl-bis(aminoethyl)ether, andN′-(3-(dimethylamino)propyl)-N,N-dimethyl-1,3-propanediamine.

In certain embodiments, bis(sulfonyl)alkanol-containing polythioethersprovided by the present disclosure are characterized by a mercaptanequivalent weight (MEW) from about 400 to about 4,000.

Various methods can be used to prepare thiol-terminated polythioethersof Formula (18a) and Formula (18b). Examples of suitablethiol-terminated polythioethers, and methods for their production, aredescribed in U.S. Pat. No. 6,172,179 at col. 2, line 29 to col. 4, line22; col. 6, line 39 to col. 10, line 50; and col. 11, lines 65 to col.12, line 22, the cited portions of which are incorporated by reference.Such thiol-terminated polythioethers may be difunctional, that is,linear polymers having two terminal thiol groups, or polyfunctional,that is, branched polymers have three or more terminal thiol groups.Suitable thiol-terminated polythioethers are commercially available, forexample, as Permapol® P3.1E, from PRC-DeSoto International Inc., Sylmar,Calif.

In certain embodiments, a thiol-terminated polythioether can be preparedby reacting a polythiol and a diene such as a divinyl ether, and therespective amounts of the reactants used to prepare the polythioethersare chosen to yield terminal thiol groups. Thus, in some cases, (nor >n, such as n+1) moles of a polythiol, such as a dithiol or a mixtureof at least two different dithiols and about 0.05 moles to 1 moles, suchas 0.1 moles to 0.8 moles, of a thiol-terminated polyfunctionalizingagent may be reacted with (n) moles of a diene, such as a divinyl ether,or a mixture of at least two different dienes, such as a divinyl ether.In certain embodiments, a thiol-terminated polyfunctionalizing agent ispresent in the reaction mixture in an amount sufficient to provide athiol-terminated polythioether having an average functionality of from2.05 to 3, such as 2.1 to 2.8.

The reaction used to make a thiol-terminated polythioether may becatalyzed by a free radical catalyst. Suitable free radical catalystsinclude azo compounds, for example azobisnitrile compounds such asazo(bis)isobutyronitrile (AIBN); organic peroxides, such as benzoylperoxide and t-butyl peroxide; and inorganic peroxides, such as hydrogenperoxide. The reaction can also be effected by irradiation withultraviolet light either with or without a radicalinitiator/photosensitizer. Ionic catalysis methods, using eitherinorganic or organic bases, e.g., triethylamine, may also be used.

Suitable thiol-terminated polythioethers may be produced by reacting adivinyl ether or mixtures of divinyl ethers with an excess of dithiol ora mixtures of dithiols.

Thus, in certain embodiments, a thiol-terminated polythioether comprisesthe reaction product of reactants comprising:

(a) a dithiol of Formula (23):HS—R¹—SH  (23)

-   -   wherein:        -   R¹ is selected from C₂₋₆ alkanediyl, C₆₋₈ cycloalkanediyl,            C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈ heterocycloalkanediyl, and            —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—; wherein:            -   each R³ is independently selected from hydrogen and                methyl;            -   each X is independently selected from —O—, —S—, —NH—,                and —NR— wherein R is selected from hydrogen and methyl;            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5; and            -   r is an integer from 2 to 10; and

(b) a divinyl ether of Formula (24):CH₂═CH—O—[—R²—O—]_(m)—CH═CH₂  (24)

-   -   wherein:        -   each R² is independently selected from C₁₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and            —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined above;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6.            And, in certain embodiments, the reactants may comprise (c)            a polyfunctional compound such as a polyfunctional compound            B (—V)_(z), where B, —V, and z are as defined herein.

In certain embodiments, dithiols suitable for use in preparingthiol-terminated polythioethers include those having Formula (23), otherdithiols disclosed herein, or combinations of any of the dithiolsdisclosed herein. In certain embodiments, a dithiol has the structure ofFormula (23):HS—R¹—SH  (23)

wherein:

-   -   R¹ is selected from C₂₋₆ alkanediyl, C₆₋₈ cycloalkanediyl, C₆₋₁₀        alkanecycloalkanediyl, C₅₋₈ heterocycloalkanediyl, and        —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—;    -   wherein:        -   each R³ is independently selected from hydrogen and methyl;        -   each X is independently selected from —O—, —S—, and —NR⁵—            wherein R⁵ is selected from hydrogen and methyl;        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5; and        -   r is an integer from 2 to 10.

In certain embodiments of a dithiol of Formula (23), R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—.

In certain embodiments of a compound of Formula (23), X is selected from—O— and —S—, and thus —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)— in Formula (23)is —[—(CHR³—)_(s)—O—]_(q)—(CHR³)_(r)— or —[(—CHR³₂—)_(s)—S—]_(q)—(CHR³)_(r)—. In certain embodiments, p and r are equal,such as where p and r are both two.

In certain embodiments of a dithiol of Formula (23), R¹ is selected fromC₂₋₆ alkanediyl and —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—.

In certain embodiments of a dithiol of Formula (23), R¹ is—[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, and in certain embodiments X is —O—,and in certain embodiments, X is —S—.

In certain embodiments where R¹ is —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—, sis 2, r is 2, q is 1, and X is —S—; in certain embodiments, wherein s is2, q is 2, r is 2, and X is —O—; and in certain embodiments, s is 2, ris 2, q is 1, and X is —O—.

In certain embodiments where R¹ is —[—(CHR³)_(s)—X—]_(q)—(CHR³)_(r)—,each R³ is hydrogen, and in certain embodiments, at least one R³ ismethyl.

Examples of suitable dithiols include, for example, 1,2-ethanedithiol,1,2-propanedithiol, 1,3-propanedithiol, 1,3-butanedithiol,1,4-butanedithiol, 2,3-butanedithiol, 1,3-pentanedithiol,1,5-pentanedithiol, 1,6-hexanedithiol, 1,3-dimercapto-3-methylbutane,dipentenedimercaptan, ethylcyclohexyldithiol (ECHDT),dimercaptodiethylsulfide, methyl-substituted dimercaptodiethylsulfide,dimethyl-substituted dimercaptodiethylsulfide, dimercaptodioxaoctane,1,5-dimercapto-3-oxapentane, and a combination of any of the foregoing.A polythiol may have one or more pendant groups selected from a lower(e.g., C₁₋₆) alkyl group, a lower alkoxy group, and a hydroxyl group.Suitable alkyl pendant groups include, for example, C₁₋₆ linear alkyl,C₃₋₆ branched alkyl, cyclopentyl, and cyclohexyl.

Other examples of suitable dithiols include dimercaptodiethylsulfide(DMDS) (in Formula (23), R¹ is —[—(CH₂—)_(s)—X—]_(q)—(CH₂)_(r)—, whereins is 2, r is 2, q is 1, and X is —S—); dimercaptodioxaoctane (DMDO) (inFormula (23), R¹ is —[—(CH₂—)_(s)—X—]_(q)—(CH₂)_(r)—, wherein s is 2, qis 2, r is 2, and X is —O—); and 1,5-dimercapto-3-oxapentane (in Formula(23), R¹ is —[(—CH₂—)_(s)—X—]_(q)—(CH₂)_(r)—, wherein s is 2, r is 2, qis 1, and X is —O—). It is also possible to use dithiols that includeboth heteroatoms in the carbon backbone and pendant alkyl groups, suchas methyl groups. Such compounds include, for example,methyl-substituted DMDS, such as HS—CH₂CH(CH₃)—S—CH₂CH₂—SH,HS—CH(CH₃)CH₂—S—CH₂CH₂—SH and dimethyl substituted DMDS, such asHS—CH₂CH(CH₃)—S—CHCH₃CH₂—SH and HS—CH(CH₃)CH₂—S—CH₂CH(CH₃)—SH.

Suitable divinyl ethers for preparing polythioethers include, forexample, divinyl ethers of Formula (24):CH₂═CH—O—R²—O—)_(m)—CH═CH₂  (24)where R² in Formula (24) is selected from a C₂₋₆ n-alkanediyl group, aC₃₋₆ branched alkanediyl group, a C₆₋₈ cycloalkanediyl group, a C₆₋₁₀alkanecycloalkanediyl group, and —[—(CH₂—)_(s)—O-]_(q)—(—CH₂—)_(r)—,where s is an integer ranging from 2 to 6, q is an integer from 1 to 5,and r is an integer from 2 to 10. In certain embodiments of a divinylether of Formula (24), R² is a C₂₋₆ n-alkanediyl group, a C₃₋₆ branchedalkanediyl group, a C₆₋₈ cycloalkanediyl group, a C₆₋₁₀alkanecycloalkanediyl group, and in certain embodiments,—[(—CH₂—)_(s)—O—]_(q)—(—CH₂—)_(r)—.

Suitable divinyl ethers include, for example, compounds having at leastone oxyalkanediyl group, such as from 1 to 4 oxyalkanediyl groups, i.e.,compounds in which m in Formula (24) is an integer ranging from 1 to 4.In certain embodiments, m in Formula (24) is an integer ranging from 2to 4. It is also possible to employ commercially available divinyl ethermixtures that are characterized by a non-integral average value for thenumber of oxyalkanediyl units per molecule. Thus, m in Formula (24) canalso take on rational number values ranging from 0 to 10.0, such as from1.0 to 10.0, from 1.0 to 4.0, or from 2.0 to 4.0.

Examples of suitable vinyl ethers include, divinyl ether, ethyleneglycol divinyl ether (EG-DVE) (R² in Formula (24) is ethanediyl and m is1), butanediol divinyl ether (BD-DVE) (R² in Formula (24) is butanediyland m is 1), hexanediol divinyl ether (HD-DVE) (R² in Formula (24) ishexanediyl and m is 1), diethylene glycol divinyl ether (DEG-DVE) (R² inFormula (24) is ethanediyl and m is 2), triethylene glycol divinyl ether(R² in Formula (24) is ethanediyl and m is 3), tetraethylene glycoldivinyl ether (R² in Formula (24) is ethanediyl and m is 4),cyclohexanedimethanol divinyl ether, polytetrahydrofuryl divinyl ether;trivinyl ether monomers, such as trimethylolpropane trivinyl ether;tetrafunctional ether monomers, such as pentaerythritol tetravinylether; and combinations of two or more such polyvinyl ether monomers. Apolyvinyl ether may have one or more pendant groups selected from alkylgroups, hydroxyl groups, alkoxy groups, and amine groups.

In certain embodiments, divinyl ethers in which R² in Formula (24) isC₃₋₆ branched alkanediyl may be prepared by reacting a polyhydroxycompound with acetylene. Examples of divinyl ethers of this type includecompounds in which R² in Formula (24) is an alkyl-substitutedmethanediyl group such as —CH(—CH₃)—, for which R² in Formula (24) isethanediyl and m is 3.8) or an alkyl-substituted ethanediyl.

Other useful divinyl ethers include compounds in which R² in Formula(24) is polytetrahydrofuryl (poly-THF) or polyoxyalkanediyl, such asthose having an average of about 3 monomer units.

Two or more types of polyvinyl ether monomers of Formula (24) may beused. Thus, in certain embodiments, two dithiols of Formula (23) and onepolyvinyl ether monomer of Formula (24), one dithiol of Formula (23) andtwo polyvinyl ether monomers of Formula (24), two dithiols of Formula(23) and two divinyl ether monomers of Formula (24), and more than twocompounds of one or both Formula (23) and Formula (24), may be used toproduce a variety of thiol-terminated polythioethers.

In certain embodiments, a polyvinyl ether monomer comprises 20 to lessthan 50 mole percent of the reactants used to prepare a thiol-terminatedpolythioether, and in certain embodiments, 30 to less than 50 molepercent.

In certain embodiments provided by the present disclosure, relativeamounts of dithiols and divinyl ethers are selected to yieldpolythioethers having terminal thiol groups. Thus, a dithiol of Formula(23) or a mixture of at least two different dithiols of Formula (23),are reacted with of a divinyl ether of Formula (24) or a mixture of atleast two different divinyl ethers of Formula (24) in relative amountssuch that the molar ratio of thiol groups to vinyl groups is greaterthan 1:1, such as 1.1 to 2.0:1.0.

The reaction between dithiols and divinyl ethers and/or polythiols andpolyvinyl ethers may be catalyzed by a free radical catalyst. Suitablefree radical catalysts include, for example, azo compounds, for exampleazobisnitriles such as azo(bis)isobutyronitrile (AIBN); organicperoxides such as benzoyl peroxide and t-butyl peroxide; and inorganicperoxides such as hydrogen peroxide. The catalyst may be a free-radicalcatalyst, an ionic catalyst, or ultraviolet radiation. In certainembodiments, the catalyst does not comprise acidic or basic compounds,and does not produce acidic or basic compounds upon decomposition.Examples of free-radical catalysts include azo-type catalyst, such asVazo®-57 (Du Pont), Vazo®-64 (Du Pont), Vazo®-67 (Du Pont), V-70® (WakoSpecialty Chemicals), and V-65B® (Wako Specialty Chemicals). Examples ofother free-radical catalysts are alkyl peroxides, such as t-butylperoxide. The reaction may also be effected by irradiation withultraviolet light either with or without a cationic photoinitiatingmoiety.

Thiol-terminated polythioethers provided by the present disclosure maybe prepared by combining at least one compound of Formula (23) and atleast one compound of Formula (24) followed by addition of anappropriate catalyst, and carrying out the reaction at a temperaturefrom 30° C. to 120° C., such as 70° C. to 90° C., for a time from 2 to24 hours, such as 2 to 6 hours.

As disclosed herein, thiol-terminated polythioethers may comprise apolyfunctional polythioether, i.e., may have an average functionality ofgreater than 2.0. Suitable polyfunctional thiol-terminatedpolythioethers include, for example, those having the structure ofFormula (28a):{HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′—}_(z)B  (18a)wherein z has an average value of greater than 2.0, and, in certainembodiments, a value between 2 and 3, a value between 2 and 4, a valuebetween 3 and 6, and in certain embodiments, is an integer from 3 to 6.

Polyfunctionalizing agents suitable for use in preparing suchpolyfunctional thiol-terminated polymers include trifunctionalizingagents, that is, compounds where z is 3. Suitable trifunctionalizingagents include, for example, triallyl cyanurate (TAC),1,2,3-propanetrithiol, isocyanurate-containing trithiols, andcombinations thereof, as disclosed in U.S. Publication No. 2010/0010133at paragraphs [0102]-[0105], the cited portion of which is incorporatedby reference and isocyanurates as disclosed, for example, in U.S.Application Publication No. 2011/0319559, which is incorporated byreference. Other useful polyfunctionalizing agents includetrimethylolpropane trivinyl ether, and the polythiols described in U.S.Pat. Nos. 4,366,307; 4,609,762; and 5,225,472, each of which isincorporated by reference. Mixtures of polyfunctionalizing agents mayalso be used. As a result, bis(sulfonyl)alkanol-containingpolythioethers provided by the present disclosure may have a wide rangeof average functionality. For example, trifunctionalizing agents mayafford average functionalities from 2.05 to 3.0, such as from 2.1 to2.6. Wider ranges of average functionality may be achieved by usingtetrafunctional or higher functionality polyfunctionalizing agents.Functionality may also be determined by factors such as stoichiometry,as will be understood by those skilled in the art.

Thiol-terminated polythioethers and bis(sulfonyl)alkanol-containingpolythioethers having a functionality greater than 2.0 may be preparedin a manner similar to the difunctional thiol-terminated polythioethersdescribed in U.S. Application Publication No. 2010/0010133, U.S.Application Publication No. 2011/0319559, and U.S. Pat. No. 6,172,179,each of which is incorporated by reference. In certain embodiments,polythioethers may be prepared by combining (i) one or more dithiolsdescribed herein, with (ii) one or more divinyl ethers described herein,and (iii) one or more polyfunctionalizing agents. The mixture may thenbe reacted, optionally in the presence of a suitable catalyst, to afforda thiol-terminated polythioether or bis(sulfonyl)alkanol-containingpolythioether having a functionality greater than 2.0.

In certain embodiments, polythioethers including thiol-terminatedpolythioethers, bis(sulfonyl)alkanol-containing polythioethers, andcapped analogs of any of the foregoing represent polythioethers having amolecular weight distribution. In certain embodiments, usefulpolythioethers can exhibit a number average molecular weight rangingfrom 500 Daltons to 20,000 Daltons, in certain embodiments, from 2,000Daltons to 5,000 Daltons, and in certain embodiments, from 3,000 Daltonsto 4,000 Daltons. In certain embodiments, useful polythioethers exhibita polydispersity (M_(w)/M_(n); weight average molecular weight/numberaverage molecular weight) ranging from 1 to 20, and in certainembodiments, from 1 to 5. The molecular weight distribution ofpolythioethers may be characterized, for example, by gel permeationchromatography.

Metal Ligand-Containing Prepolymers

Bis(sulfonyl)alkanols represent one type of metal ligand that may beincorporated into the backbone of a polymer such as a sulfur-containingprepolymer to improve surface adhesion. Other metal ligands may also beincorporated into the backbone of a polymer to enhance surface adhesion.In certain embodiments such as for aerospace sealant applications, themetal ligands may be selected from a ligand capable of coordinating toaluminum, aluminum oxide, Al(III), anodized aluminum, titanium, titaniumoxide, and/or Alodine® surfaces. The metal ligand may form a bidentate,tridentate, or higher order coordination complex to surface atoms. Thus,metal ligand-containing prepolymers include any of thebis(sulfonyl)alkanol-containing prepolymers disclosed herein, in whichthe bis(sulfonyl)alkanol group is replaced with another metal ligand.Similarly, methods of synthesizing metal ligand-containing prepolymers,derivatives thereof, and capped analogs thereof, include any of thosedescribed herein for the preparation of bis(sulfonyl)alkanol-containingprepolymers in which an appropriate metal chelating agent is employed.In addition to a moiety -L- comprising a metal ligand, a metal chelatingagent R⁹-L-R⁹ includes groups R⁹ comprising terminal groups reactivewith precursors of a sulfur-containing polymer. In certain embodiments,each R⁹ comprises terminal groups reactive with thiol groups such asalkenyl, epoxy, or Michael acceptor groups.

Metal ligands and in particular aluminum (III) metal ligands includehard Lewis bases such as —OH, —PO₄, —SO₄, —COOH, —C═O, and —NH₂ groups,which are capable of donating electrons to vacant orbitals of the metal.Basic donor groups effective in forming multidentate coordinationcomplexes with aluminum (III) include aliphatic monohydroxy acid anions,catecholates, aromatic hydroxy acid anions, 3-hydroxy-4-pyridinones,hydroxamates, and 3-hydroxy-2-pyridinones. Stable aluminum (III)complexes are with multidentate ligands having negative oxygen electrondonors. A metal ligand may form a multidentate complex such as abidentate complex or a tridentate complex with the metal.

In certain embodiments, a metal ligand functional group is derived froma metal chelating agent selected from a bis(sulfonyl)alkanol, ahydroxypyridinone, and an acetylacetonate.

Examples of aluminum, aluminum oxide and Al(III) chelating agentsinclude 2,3-dihydroxybenzoic acid, 5-nitrosalicylate,3-hydroxy-4-pyridinone, 3-hydroxy-2-pyridinone,2-2′-dihyrdroxyazobenzene, 8-hydroxyquinoline, oxylate, malonate,citrate, inimodiacetic acid, picolinic acid, maltol, kojic acid,N,N′-diacetic acid (EDTA), N-(2-hydroxy)ethylenediamenetriacetic acid(HEDTA), ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid (EDDHA),and N,N′-bis(hydroxybenzyl)ethylenediamine-N,N′-diacetic acid (HBED),acetoacetate, acetylacetonate, a catecholate, a hydroxamate, andquinone. Other aluminum and aluminum oxide chelators are disclosed, forexample, in Yokel, Coordination Chemistry Reviews 2002, 228, 97-113; andin Martell et al., Coordination Chemistry Reviews 1996, 149, 311-328.

Examples of titanium or titanium oxide metal ligands include H₂O₂,acetoacetonate (CH₂(COCH₃)₂), EDTA, trans-1,2-cyclohexanediamnetetraacetic acid, glycoletherdiamine tetracetic acid (GEDTA,(CH₂OCH₂CH₂N(CH₂COOH)₂)₂), diethylenetriamine pentaacetic acid (DTPA,HOOCH₂N(CH₂CH₂N(CH₂COOH)₂)₂), nitrile triacetic acid (NTA, N(CH₂COOH)₃),salicylic acid, lactic acid, acetoacetonate, triethanolamine, andcombinations of any of the foregoing.

In certain embodiments, a metal ligand comprises at least twoheteroatomic groups capable of coordinating to aluminum (III) surfaces.In certain embodiments, a metal ligand comprises at least twoheteroatomic groups selected from —OH, —PO₄, —P(O)₂—, —SO₄, —S(O)₂—,—COOH, —C═O, —NH₂, —NH—, and a combination of any of the foregoing.

In certain embodiments, a metal ligand functional group comprises amoiety selected from Formula (25a), Formula (25b), Formula (25c),Formula (25d), Formula (25e), and a combination of any of the foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e)wherein —X— is independently selected from —C(O)— or —S(O)₂—; each n isindependently selected from 1, 2, and 3; and R⁵ is a C₁₋₃ alkane-diyl.In certain embodiments, each X is —C(O)— and each n is 1; and in certainembodiments, each X is —S(O)₂— and each n is 1.

As for bis(sulfonyl)alkanol-containing polythioethers, other metalligands may be incorporated into the backbone of a prepolymer such assulfur-containing prepolymers including polythioethers. Accordingly, incertain embodiments, a metal ligand-containing prepolymer comprises amoiety of Formula (26):-A-R^(9′)-L-R^(9′)-A-  (26)wherein,

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

-   -   each A is independently a moiety of Formula (12):        —S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)    -   wherein:        -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r), wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ independently comprises hydrogen or methyl; and            -   each X independently comprises —O—, —S—, and —NR⁵—,                wherein R⁵ is selected from hydrogen and methyl; and        -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³, and            X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6.

Metal chelating agent R⁹-L-R⁹ comprises groups R⁹ that are reactivewith, for example, thiol groups and a metal ligand -L-. Metal ligand -L-may comprise, for example, a moiety of Formula (25a)-(25e). In certainembodiments, a metal chelating agent is selected from abis(sulfonyl)alkanol, a hydroxypyridinone, an acetylacetonate, and acombination of any of the foregoing.

In certain embodiments, a metal ligand-containing prepolymer comprises ametal ligand-containing polythioether of Formula (28a), a metalligand-containing polythioether of Formula (28b), or a combinationthereof:R⁶-A-[-R^(9′)-L-R^(9′)-A-]_(N)—R⁶  (28a){R⁶-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′—}_(z)B  (28b)

wherein,

-   -   N is an integer from 1 to 10;    -   each R^(9′) is independently a moiety derived from the reaction        of R⁹ of a metal chelating agent R⁹-L-R⁹ with a thiol group,        wherein each R⁹ comprises a terminal group reactive with a        thiol; and L comprises a metal ligand;    -   each A is independently a moiety of Formula (12):        —S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)    -   wherein:        -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ independently comprises hydrogen or methyl; and            -   each X independently —O—, —S—, or —NR⁵—, wherein R⁵ is                selected from hydrogen and methyl;    -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or        —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and

p is an integer from 2 to 6;

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a terminal group reactive with        terminal thiol groups; and    -   each —V′— is derived from the reaction of —V with a thiol; and

each R⁶ independently comprises hydrogen or a moiety having a terminalreactive group.

In certain embodiments of a prepolymer of Formula (28a) and Formula(28b), each R⁶ is hydrogen.

In certain embodiments of a prepolymer of Formula (28a) and Formula(28b), each R⁶ is the same and the terminal reactive group is selectedfrom —SH, —CH═CH₂, —NH₂, —OH, an epoxy group, a polyalkoxysilyl group,an isocyanate group, and a Michael acceptor group.

In certain embodiments, a thiol-terminated metal ligand-containingpolythioether comprises the reaction product of reactants comprising:

(a) a thiol-terminated polythioether comprising a thiol-terminatedpolythioether of Formula (18a), a thiol-terminated polythioether ofFormula (18b), or a combination thereof:HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a){HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′—}_(z)B  (18b)

wherein:

-   -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, or —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ independently comprises hydrogen or methyl; and        -   each X independently comprises —O—, —S—, or —NR⁵—, wherein            R⁵ is selected from hydrogen and methyl;    -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or        —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60;    -   p is an integer from 2 to 6; and    -   B represents a core of a z-valent polyfunctionalizing agent        B(—V)_(z) wherein:        -   z is an integer from 3 to 6;        -   each V is a group comprising a terminal group reactive with            terminal thiol groups; and    -   each —V′— is derived from the reaction of —V with a thiol; and

(b) a metal chelating agent R⁹-L-R⁹ where each R⁹ is independently amoiety comprising a terminal group reactive with a thiol group; and -L-is a moiety comprising a metal ligand.

In certain embodiments of Formula (18a) and Formula (18b), a metalligand may comprise a moiety selected from Formula (25a), Formula (25b),Formula (25c), Formula (25d), Formula (25e), and a combination of any ofthe foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e)

wherein,

-   -   —X— is independently selected from —C(O)— or —S(O)₂—;    -   each n is independently selected from 1, 2, and 3; and    -   R⁵ is a C₁₋₃ alkane-diyl.

In certain embodiments of Formula (18a) and Formula (18b), a metalligand comprises a bis(sulfonyl)alkanol, a hydroxypyridinone, anacetylacetonate, or a combination of any of the foregoing.

In certain embodiments, the polythioether of Formula (18a) comprises thereaction product of 1,8-dimercapto-3,6-dioxaoctane and diethylene glycoldivinyl ether.

In certain embodiments, the polythioether of Formula (18b) comprises thereaction product of 1,8-dimercapto-3,6-dioxaoctane, diethylene glycoldivinyl ether, and triallyl cyanurate.

In certain embodiments, a thiol-terminated metal ligand-containingpolythioether prepolymer comprises the reaction product of reactantscomprising:

-   -   (a) a thiol-terminated metal ligand-containing polythioether        comprising a thiol-terminated metal ligand-containing        polythioether of Formula (29a), a thiol-terminated metal        ligand-containing polythioether of Formula (29b), or a        combination thereof:        H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)        {H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′—}_(z)B  (29b)        wherein:

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:        -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ independently comprises hydrogen or methyl; and            -   each X independently —O—, —S—, or —NR⁵—, wherein R⁵ is                selected from hydrogen and methyl;        -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or            —[(—CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6;

B represents a core of a z-valent, alkenyl-terminatedpolyfunctionalizing agent B(—V)_(z) wherein:

-   -   z is an integer from 3 to 6; and    -   each V is a group comprising a terminal alkenyl group; and

each —V′— is derived from the reaction of —V with a thiol; and

(b) a polyalkenyl compound.

In certain embodiments of polythioethers of Formula (29a) and Formula(29b), the metal ligand comprises a moiety selected from Formula (25a),Formula (25b), Formula (25c), Formula (25d), Formula (25e), and acombination of any of the foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e)

wherein,

-   -   —X— is independently selected from —C(O)— or —S(O)₂—;    -   each n is independently selected from 1, 2, and 3; and    -   R⁵ is a C₁₋₃ alkane-diyl.

In certain embodiments of the thiol-terminated metal ligand-containingpolythioethers of Formula (29a) and Formula (29b), the polyalkenylcompound comprises diethylene glycol divinyl ether, triallyl cyanurate,or a combination thereof.

In certain embodiments, a method of preparing a thiol-terminated metalligand-containing polythioether of Formula (29a), comprises reacting(N+1) moles of a thiol-terminated polythioether of Formula (18a) with(N) moles of a metal chelating agent comprising -L- and terminal groupsreactive with thiol groups:H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a)wherein:

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:    -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, or —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ independently comprises hydrogen or methyl; and        -   each X independently comprises —O—, —S—, or —NR⁵—, wherein            R⁵ comprises hydrogen or methyl; and    -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or        —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and    -   p is an integer from 2 to 6.

In certain embodiments of the preceding method, the metal ligandcomprises a moiety selected from Formula (25a), Formula (25b), Formula(25c), Formula (25d), Formula (25e), and a combination of any of theforegoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e)

wherein,

-   -   —X— is independently selected from —C(O)— or —S(O)₂—;    -   each n is independently selected from 1, 2, and 3; and    -   R⁵ is a C₁₋₃ alkane-diyl.

In certain embodiments of the preceding method, the metal chelatingagent comprises a bis(sulfonyl)alkanol, a hydroxypyridinone, anacetylacetonate, or a combination of any of the foregoing.

In certain embodiments, methods of preparing a thiol-terminated metalligand-containing polythioether of Formula (29b) comprise reacting (z)moles of a thiol-terminated metal ligand-containing polythioether ofFormula (29a) with one (1) mole of a polyfunctionalizing agent B{V}_(z):{H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′—}_(z)B  (29b)H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)wherein:

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

-   -   each A is independently a moiety of Formula (12):        —S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)    -   wherein:        -   each R¹ independently comprises C₂₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, or            —[(CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r), wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ independently comprises hydrogen or methyl; and            -   each X independently comprises —O—, —S—, or —NR⁵—,                wherein R⁵ comprises hydrogen or methyl;        -   each R² independently comprises C₁₋₁₀ alkanediyl, C₆₋₈            cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, or            —[(—CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6; and

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a terminal group reactive with a        terminal thiol group; and    -   each —V′— is derived from the reaction of —V with a thiol.

In certain embodiments of the preceding method, the metal ligandcomprises a moiety selected from Formula (25a), Formula (25b), Formula(25c), Formula (25d), Formula (25e), and a combination of any of theforegoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e)

wherein,

-   -   —X— is independently selected from —C(O)— or —S(O)₂—;    -   each n is independently selected from 1, 2, and 3; and    -   R⁵ is a C₁₋₃ alkane-diyl.

In certain embodiments of the preceding method, the metal chelatingagent is selected from a bis(sulfonyl)alkanol, a hydroxypyridinone, anacetylacetonate, or a combination of any of the foregoing.

Metal Ligand-Containing Sulfur-Containing Prepolymers

In addition to polythioether prepolymers, metal ligands may beincorporated into the backbone of other polymers such as othersulfur-containing polymers to improve adhesion. A sulfur-containingpolymer can be any polymer having at least one sulfur atom in therepeating unit, including, but not limited to, polymeric thiols,polythiols, thioethers, polythioethers, sulfur-containing polyformals,and polysulfides. A “thiol,” as used herein, refers to a compoundcomprising a thiol or mercaptan group, that is, an “SH” group, either asthe sole functional group or in combination with other functionalgroups, such as hydroxyl groups, as is the case with, for example,thioglycerols. A polythiol refers to such a compound having more thanone SH group, such as a dithiol or higher functionality thiol. Suchgroups are typically terminal and/or pendant such that they have anactive hydrogen that is reactive with other functional groups. Apolythiol can comprise both a terminal and/or pendant sulfur (—SH) and anon-reactive sulfur atom (—S— or —S—S—). Thus, the term polythiolgenerally encompasses polythioethers and polysulfides.

The term polysulfide refers to a polymer that contains one or moresulfide linkages, i.e.,—Sx-linkages, where x is from 2 to 4, in thepolymer backbone and/or in pendant positions on the polymer chain. Incertain embodiments, the polysulfide polymer will have two or moresulfur-sulfur linkages.

Suitable polysulfides are commercially available, for example, from AkzoNobel and Toray Fine Chemicals under the names Thiokol-LP andThioplast®. Thioplast® products are available in a wide range ofmolecular weights ranging, for example, from less than 1,100 to over8,000, with molecular weight being the average molecular weight in gramsper mole. In some cases, the polysulfide has a number average molecularweight of 1,000 Daltons to 4,000 Daltons.

Sulfur-containing polyformal prepolymers useful in aerospace sealantapplications are disclosed, for example, in U.S. Application PublicationNo. 2012/0234205 and in U.S. Application Publication No. 2012/0238707.

Methods of Synthesizing Bis(Sulfonyl)Alkanol-Containing Polythioethers

In general, thiol-terminated bis(sulfonyl)alkanol-containingpolythioethers may be prepared by reacting a thiol-terminatedpolythioether or a mixture of thiol-terminated polythioethers with abis(sulfonyl)alkanol such as a bis(vinylsulfonyl)alkanol. In certainembodiments, a thiol-terminated bis(sulfonyl)alkanol-containingpolythioether may be prepared by reacting a difunctionalthiol-terminated polythioether or a mixture of difunctionalthiol-terminated polythioethers with a bis(sulfonyl)alkanol such as abis(vinylsulfonyl)alkanol or a bis(sulfonyl)alkanol having terminalgroups reactive with thiol groups.

In certain embodiments, methods of preparing a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (16a), comprisereacting (N+1) moles of a thiol-terminated polythioether of Formula(18a) with (N) moles of a bis(sulfonyl)alkanol of Formula (4a):H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)-H  (16a)HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a)R⁸—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R⁸  (4a)wherein:

N is an integer from 1 to 10;

each R⁸ is independently selected from a moiety comprising a terminalgroup reactive with a terminal thiol group;

each R^(8′) is a moiety derived from the reaction of abis(sulfonyl)alkanol with thiol groups;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NR⁵—,            wherein R⁵ is selected from hydrogen and methyl; and    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and    -   p is an integer from 2 to 6.

In certain embodiments of thiol-terminatedbis(sulfonyl)alkanol-containing polythioethers of Formula (16a), N is 1,2, 3, 4, 5, 6, 7, 8, 9, and in certain embodiments N is 10. In certainembodiments of bis(sulfonyl)alkanol-containing polymers of Formula(16a), the molecular weight is from 200 Daltons to 20,000 Daltons. Incertain embodiments, thiol-terminated bis(sulfonyl)alkanol-containingpolythioethers of Formula (16a) comprise a combination ofbis(sulfonyl)alkanol containing polythioethers of Formula (16a) withdifferent values for N. In certain embodiments of thiol-terminatedbis(sulfonyl)alkanol-containing polythioethers of Formula (16a), N is 1.Thus, in practice, when preparing a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (16a), themolar ratios of thiol-terminated polythioether to bis(sulfonyl)alkanolneed not be a whole number such that thiol-terminatedbis(sulfonyl)alkanol-containing polythioethers of Formula (16a)represent a mixture of thiol-terminated bis(sulfonyl)alkanol-containingpolythioethers having different values of N.

In certain embodiments, methods of preparing a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (16b) comprisereacting (z) moles of a thiol-terminated bis(sulfonyl)alkanol-containingpolythioether of Formula (16a) with one (1) mole of apolyfunctionalizing agent B {V}_(z):{H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)—V′—}_(z)B  (16b)H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)-H  (16a)wherein:

each R^(8′) is a moiety derived from the reaction of abis(sulfonyl)alkanol with thiol groups;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:        -   each R¹ independently is selected from C₂₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, and            —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ is independently selected from hydrogen and                methyl; and            -   each X is independently selected from —O—, —S—, and                —NR⁵—, wherein R⁵ is selected from hydrogen and methyl;        -   each R² is independently selected from C₁₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and            —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6; and

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a group reactive with a thiol        group; and    -   each —V′— is derived from the reaction of —V with a thiol.

In certain embodiments, the reaction between a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether and bis(sulfonyl)alkanolsuch as a bis(vinylsulfonyl)alkanol is performed in the presence of acatalyst such as an amine catalyst including, for example, any of theamine catalysts disclosed herein.

Methods of Synthesizing Thiol-Terminated Metal Ligand-ContainingPrepolymers

In certain embodiments, a thiol-terminated metal ligand-containingprepolymer such as a thiol-terminated metal ligand-containingpolythioether may be prepared by reacting a difunctionalthiol-terminated prepolymer or a mixture of difunctionalthiol-terminated prepolymers with a metal chelating agent having atleast two groups reactive with thiol groups such as abis(sulfonyl)alkanol, a hydroxypyridinone or a acetylacetonate having atleast two terminal groups reactive with thiol groups.

In certain embodiments, methods of preparing a thiol-terminated metalligand-containing prepolymer of Formula (29a), comprise reacting (N+1)moles of a thiol-terminated polythioether of Formula (18a) with (N)moles of a metal chelating agent R⁹-L-R⁹:H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a)wherein:

N is an integer from 1 to 10;

each R^(9′) is independently a moiety derived from the reaction of R⁹ ofa metal chelating agent R⁹-L-R⁹ with a thiol group, wherein each R⁹comprises a terminal group reactive with a thiol; and L comprises ametal ligand;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

wherein:

-   -   each R¹ independently is selected from C₂₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈        heterocycloalkanediyl, and —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—,        wherein:        -   s is an integer from 2 to 6;        -   q is an integer from 1 to 5;        -   r is an integer from 2 to 10;        -   each R³ is independently selected from hydrogen and methyl;            and        -   each X is independently selected from —O—, —S—, and —NR⁵—,            wherein R⁵ is selected from hydrogen and methyl; and    -   each R² is independently selected from C₁₋₁₀ alkanediyl, C₆₋₈        cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and        —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³, and X        are as defined for R¹;    -   m is an integer from 0 to 50;    -   n is an integer from 1 to 60; and    -   p is an integer from 2 to 6.

In certain embodiments of thiol-terminated metal ligand-containingpolythioethers of Formula (29a), N is 1, 2, 3, 4, 5, 6, 7, 8, 9, and incertain embodiments N is 10. In certain embodiments of metalligand-containing prepolymer of Formula (29a), the molecular weight isfrom 200 Daltons to 20,000 Daltons. In certain embodiments,thiol-terminated metal ligand-containing prepolymers of Formula (6)comprise a combination of metal ligand-containing prepolymers of Formula(29a) with different values for N. In certain embodiments ofthiol-terminated metal ligand-containing prepolymers of Formula (29a), Nis 1. Thus, in practice, when preparing a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (29a), themolar ratios of thiol-terminated polythioether to metal chelating agentneed not be a whole number such that thiol-terminated metalligand-containing prepolymers of Formula (29a) represent a mixture ofthiol-terminated metal ligand-containing prepolymers having differentvalues of N.

In certain embodiments, methods of preparing a thiol-terminated metalligand-containing prepolymer of Formula (29b) comprise reacting (z)moles of a thiol-terminated metal ligand-containing prepolymer ofFormula (29a) with one (1) mole of a polyfunctionalizing agent B{V}_(z):{H-A-[-R^(9′)-L-R^(9′)-A-]_(N)—V′—}_(z)B  (29b)H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a)wherein:

-   -   each R^(9′) is independently a moiety derived from the reaction        of R⁹ of a metal chelating agent R⁹-L-R⁹ with a thiol group,        wherein each R⁹ comprises a terminal group reactive with a        thiol; and L comprises a metal ligand;    -   each R¹⁰ is independently selected from C₁₋₃ alkanediyl and        substituted C₁₋₃ alkanediyl, wherein one or more substituent        groups is —OH;    -   each A is independently a moiety of Formula (12):        —S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)    -   wherein:        -   each R¹ independently is selected from C₂₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, and            —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ is independently selected from hydrogen and                methyl; and            -   each X is independently selected from —O—, —S—, and                —NR⁵—, wherein R⁵ is selected from hydrogen and methyl;        -   each R² is independently selected from C₁₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and            —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6; and

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a group reactive with a thiol        group; and    -   each —V′— is derived from the reaction of —V with a thiol.

In certain embodiments, the reaction between a thiol-terminated metalligand-containing polythioether and metal chelating agent is performedin the presence of a catalyst such as an amine catalyst including, forexample, any of the amine catalysts disclosed herein.

Alkenyl-Terminated Bis(Sulfonyl)Alkanol-Containing PolythioetherPrepolymers

Thiol-terminated bis(sulfonyl)alkanol-containing polythioethers providedby the present disclosure can be reacted with polyalkenyls such asdialkenyl ethers and/or alkenyl-terminated polyfunctionalizing agents toprovide alkenyl-terminated bis(sulfonyl)alkanol-containing polythioetherprepolymers. Alkenyl-terminated bis(sulfonyl)alkanol-containingpolythioether prepolymers may be combined with a curing agent to providea curable composition such as a sealant composition.

For example, in certain embodiments an alkenyl-terminatedbis(sulfonyl)alkanol-containing polythioether prepolymer comprises thereaction product of reactants comprising:

(a) a thiol-terminated bis(sulfonyl)alkanol-containing polythioetherselected from a thiol-terminated bis(sulfonyl)alkanol-containingpolythioether of Formula (16a), a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether of Formula (16b), and acombination thereof:H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)-H  (16a){H-A-[-R^(8′)—S(O)₂—R¹⁰—CH(—OH)—R¹⁰—S(O)₂—R^(8′)-A-]_(N)—V′—}_(z)B  (16b)wherein

N is an integer from 1 to 10;

each R^(8′) is a moiety derived from the reaction of abis(sulfonyl)alkanol with thiol groups;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:        -   each R¹ independently is selected from C₂₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, and            —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ is independently selected from hydrogen and                methyl; and            -   each X is independently selected from —O—, —S—, and                —NR⁵—, wherein R⁵ is selected from hydrogen and methyl;        -   each R² is independently selected from C₁₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and            —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6;

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a terminal group reactive with a        thiol group; and    -   each —V′— is derived from the reaction of —V with a thiol; and

(b) a polyalkenyl compound.

In certain embodiments, a polyalkenyl compound is selected from adivinyl ether or a mixture of divinyl ethers including any of thosedisclosed herein, an alkenyl-terminated polyfunctionalizing agent, and acombination thereof.

In certain embodiments of the preceding reaction, (a) is polythioetherof Formula (16a), and (b) is a polyvinyl ether selected from a divinylether, an alkenyl-terminated polyfunctionalizing agent and a combinationthereof.

In certain embodiments of the preceding reaction, (a) is anpolythioether of Formula (16a), and (b) is a polyalkenyl ether selectedfrom diethylene glycol divinyl ether (DEG-DVE), TAC, and a combinationthereof.

Alkenyl-Terminated Metal Ligand-Containing Polythioether Prepolymers

Thiol-terminated metal ligand-containing prepolymers provided by thepresent disclosure can be reacted with polyalkenyls such as dialkenylethers and/or alkenyl-terminated polyfunctionalizing agents to providealkenyl-terminated metal ligand-containing prepolymers.Alkenyl-terminated metal ligand-containing prepolymers may be combinedwith a curing agent to provide a curable composition such as a sealantcomposition.

For example, in certain embodiments an alkenyl-terminated metalligand-containing prepolymer comprises the reaction product of reactantscomprising:

(a) a thiol-terminated metal ligand-containing prepolymer selected froma thiol-terminated metal ligand-containing polythioether of Formula(29a), a metal ligand-containing polythioether of Formula (29b), and acombination thereof:H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (19a){H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′—}_(z)B  (29b)wherein,

N is an integer from 1 to 10;

each R^(9′) is a moiety derived from the reaction of a metal chelatingagent R⁹-L-R⁹ with thiol groups, wherein -L- comprises a metal group andeach R⁹ comprises a group reactive with a thiol group;

each R¹⁰ is independently selected from C₁₋₃ alkanediyl and substitutedC₁₋₃ alkanediyl, wherein one or more substituent groups is —OH;

each A is independently a moiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12)

-   -   wherein:        -   each R¹ independently is selected from C₂₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₀ alkanecycloalkanediyl, C₅₋₈            heterocycloalkanediyl, and            —[(—CHR³—)_(s)—X—]_(q)—(—CHR³—)_(r)—, wherein:            -   s is an integer from 2 to 6;            -   q is an integer from 1 to 5;            -   r is an integer from 2 to 10;            -   each R³ is independently selected from hydrogen and                methyl; and            -   each X is independently selected from —O—, —S—, and                —NR⁵—, wherein R⁵ is selected from hydrogen and methyl;        -   each R² is independently selected from C₁₋₁₀ alkanediyl,            C₆₋₈ cycloalkanediyl, C₆₋₁₄ alkanecycloalkanediyl, and            —[—(CHR³—)_(s)—X—]_(q)—(CHR³—)_(r)—, wherein s, q, r, R³,            and X are as defined for R¹;        -   m is an integer from 0 to 50;        -   n is an integer from 1 to 60; and        -   p is an integer from 2 to 6;

B represents a core of a z-valent polyfunctionalizing agent B(—V)_(z)wherein:

-   -   z is an integer from 3 to 6;    -   each V is a group comprising a terminal group reactive with a        thiol group; and    -   each —V′— is derived from the reaction of —V with a thiol; and

(b) a polyalkenyl compound.

In certain embodiments, a polyalkenyl compound is selected from adivinyl ether or a mixture of divinyl ethers including any of thosedisclosed herein, an alkenyl-terminated polyfunctionalizing agent, and acombination thereof.

In certain embodiments of the preceding reaction, (a) is polythioetherof Formula (29a), and (b) is a polyvinyl ether selected from a divinylether, an alkenyl-terminated polyfunctionalizing agent and a combinationthereof.

In certain embodiments of the preceding reaction, (a) is anpolythioether of Formula (29a), and (b) is a polyalkenyl ether selectedfrom diethylene glycol divinyl ether (DEG-DVE), TAC, and a combinationthereof.

Capped Bis(Sulfonyl)Alkanol-Containing and Metal Ligand-ContainingPrepolymers

Bis(sulfonyl)alkanol-containing polythioethers andmetal-ligand-containing prepolymers may be adapted for use with aparticular curing chemistry by capping or terminating abis(sulfonyl)alkanol-containing polythioether or metal-ligand-containingprepolymer such as a thiol-terminated bis(sulfonyl)alkanol-containingpolythioether or a thiol-terminated metal-ligand-containing prepolymerwith a suitable functional group. Capped analogs of thiol-terminatedpolythioethers are disclosed, for example, in U.S. Pat. No. 6,172,179and in U.S. Application Publication No. 2011/0319559.

For example, in certain embodiments, a bis(sulfonyl)alkanol-containingpolythioether or metal ligand-containing prepolymer has terminal groupsother than unreacted thiol groups, such as hydroxyl, alkenyl,isocyanate, amine, epoxy, a hydrolyzable functional group such as apolyalkoxysilyl group, a Michael acceptor group, or an epoxy group.

Capped analogs may be prepared by a number of methods known to thoseskilled in the art. For example, to obtain cappedbis(sulfonyl)alkanol-containing polythioethers or metalligand-containing prepolymers, a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether or a thiol-terminatedmetal ligand-containing prepolymer may be reacted with a compound havinga terminal group reactive with thiol groups.

To obtain an alkenyl-terminated bis(sulfonyl)alkanol-containingpolythioether or alkenyl-terminated metal ligand-containing prepolymer,a thiol-terminated bis(sulfonyl)alkanol-containing polythioether orthiol-terminated metal ligand-containing prepolymer may be reacted witha compound containing a terminal alkenyl group and an isocyanate groupsuch as a group derived from TMI, 2-isocyanatoethyl methacrylate, orallyl isocyanate, in the presence of dibutyltin dilaurate catalyst.

Polyalkoxysilyl-terminated bis(sulfonyl)alkanol-containingpolythioethers and polyalkoxysilyl-terminated metal ligand-containingprepolymers may be prepared, for example, by reacting a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether or a thiol-terminatedmetal ligand-containing prepolymer with anisocyanatoalkyltrialkoxysilane such as a3-isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltriethoxysilanein the presence of dibutyltin dilaurate to provide the correspondingpolyalkoxysilyl-terminated bis(sulfonyl)alkanol-containing polythioetheror corresponding polyalkoxysilyl-terminated metal ligand-containingprepolymer.

Epoxy-terminated bis(sulfonyl)alkanol-containing polythioethers andepoxy-terminated metal-ligand containing prepolymers may be prepared,for example, by reacting a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether or thiol-terminated metalligand-containing prepolymer in the presence of a monoepoxide such asallyl glycidyl ether to provide the corresponding epoxy-terminatedbis(sulfonyl)alkanol-containing polythioether or correspondingepoxy-terminated metal ligand-containing prepolymer.

Amine-terminated bis(sulfonyl)alkanol-containing polythioethers andamine-terminated metal ligand-containing prepolymers may be prepared,for example, by reacting a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether or a thiol-terminatedmetal ligand-containing prepolymer with a monofunctional 4-amino butylvinyl ether with a free-radical initiator. Alternatively, anamine-terminated bis(sulfonyl)alkanol-containing polythioether or anamine-terminated metal ligand-containing prepolymer may be obtained byreacting an isocyanate-terminated bis(sulfonyl)alkanol-containingpolythioether or an isocyanate-terminated metal ligand-containingprepolymer with a diamine such as 4-(aminomethyl)aniline to provide thecorresponding amine-terminated bis(sulfonyl)alkanol-containingpolythioether or corresponding amine-terminated metal ligand-containingprepolymer. Amine-terminated bis(sulfonyl)alkanol-containingpolythioethers and amine-terminated metal ligand-containing prepolymersmay also be obtained by reacting a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether or an alkanol-terminatedor hydroxy-terminated metal ligand-containing prepolymer with anamino-substituted benzoate such as ethyl-4-aminobenzoate in the presenceof Bu₂SnO or NaOMe at elevated temperature to provide the correspondingamine-terminated bis(sulfonyl)alkanol-containing polythioether or thecorresponding amine-terminated metal ligand-containing prepolymer.

Isocyanate-terminated bis(sulfonyl)alkanol-containing polythioethers andisocyanate-terminated metal ligand-containing prepolymers may beprepared, for example, by reacting a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether or a thiol-terminatedmetal ligand-containing prepolymer with a diisocyanate such as TDI,Isonate™ 143L (polycarbodiimide-modified diphenylmethane diisocyanate),Desmodur® N3400 (1,3-diazetidine-2,4-dione,1,3-bis(6-isocyanatohexyl)-), IPDI (isophorone diisocyanate), orDesmodur® W (H₁₂MDI) optionally in the presence of a catalyst such asdibutyltin dilaurate. Isocyanate-terminatedbis(sulfonyl)alkanol-containing polythioethers and isocyanate-terminatedmetal ligand-containing prepolymers may be used as intermediates in thesynthesis of other terminal-modified bis(sulfonyl)alkanol-containingpolythioethers and terminal-modified metal ligand-containing prepolymersuch as certain amine-terminated and thiol-terminatedbis(sulfonyl)alkanol-containing polythioether amine-terminated andthiol-terminated metal ligand-containing prepolymers.

Hydroxyl-terminated bis(sulfonyl)alkanol-containing polythioethers andhydroxy-terminated metal ligand-containing prepolymers may be prepared,for example, by reacting a thiol-terminatedbis(sulfonyl)alkanol-containing polythioether thiol-terminated metalligand-containing prepolymer with a compound having a terminal hydroxylgroup and a group reactive with thiol groups.

In certain embodiments, bis(sulfonyl)alkanol-containing polythioethersand metal ligand-containing prepolymers may be terminated with Michaelacceptor groups. In certain embodiments, a Michael acceptor group isderived from a vinyl sulfone and has the structure of Formula (27):—CH₂—C(R¹³)₂—S(O)₂—CR¹³═CH₂  (27)wherein each R¹³ is independently selected from hydrogen and C₁₋₃ alkyl.In certain embodiments of Formula (27), each R¹³ is hydrogen. In certainembodiments, Michael acceptor-terminated bis(sulfonyl)alkanol-containingpolythioethers may be prepared, for example, by reacting athiol-terminated bis(sulfonyl)alkanol-containing polythioether with acompound having a terminal Michael acceptor group and a group reactivewith thiol groups such as a divinylsulfone, in the presence of an aminecatalyst. Michael acceptor/polythioether chemistries and compounds aredisclosed in U.S. application Ser. No. 13/529,237, filed on Jun. 13,2012, which is incorporated by reference in its entirety. Examples ofisocyanate- and epoxy-capped polythioethers and methods of makingisocyanate- and epoxy-capped polythioethers are disclosed in U.S. Pat.No. 7,879,955 B2.

Compositions

Compositions provided by the present disclosure may comprise one or morebis(sulfonyl)alkanol-containing polythioethers and/or one or morebis(sulfonyl)alkanol-containing polythioether prepolymers, and/or one ormore metal ligand-containing prepolymers. Curable compositions mayfurther include a curing agent. Compositions may further includeadditives, catalysts, fillers, and/or other sulfur-containingprepolymers including for example, polythioethers, sulfur-containingpolyformals, and/or polysulfides.

A suitable curing agent is selected to be reactive with the terminalgroups of the bis(sulfonyl)alkanol-containing polythioether, metalligand-containing prepolymer, and optional sulfur-containingprepolymers.

In certain embodiments in which a bis(sulfonyl)alkanol-containingpolythioether, prepolymer thereof, or metal ligand-containing prepolymeris terminated with thiol groups, a suitable curing agent is apolyepoxide. Examples of suitable polyepoxies include, for example,polyepoxide resins such as hydantoin diepoxide, diglycidyl ether ofbisphenol-A, diglycidyl ether of bisphenol-F, Novolac® type epoxidessuch as DEN™ 438 (Dow Chemical Company), certain epoxidized unsaturatedresins, and combinations of any of the foregoing. A polyepoxide refersto a compound having two or more reactive epoxy groups. In certainembodiments, an epoxy curing agent is selected from EPON™ 828 (MomentiveSpecialty Chemicals, Inc), DEN™ 431 (Dow Chemical Company), and acombination thereof. Examples of useful curing agents that are reactivewith thiol groups include diepoxides.

In certain embodiments, a polyepoxy curing agent comprises anepoxy-functional polymer. Examples of suitable epoxy-functional polymersinclude the epoxy-functional sulfur-containing polyformal polymersdisclosed in U.S. patent application Ser. No. 13/050,988 andepoxy-functional polythioether polymers disclosed in U.S. Pat. No.7,671,145. In general, when used as a curing agent, an epoxy-functionalpolymer has a molecular weight less than about 2,000 Daltons, less thanabout 1,500, Daltons, less than about 1,000 Daltons, and in certainembodiments, less than about 500 Daltons.

In certain embodiments, a polyepoxy may comprise about 0.5 wt % to about20 wt % of the composition, from about 1 wt % to about 10 wt %, fromabout 2 wt % to about 8 wt %, from about 2 wt % to about 6 wt %, and incertain embodiments, from about 3 wt % to about 5 wt %, where wt % isbased on the total solids weight of the composition.

In certain embodiments in which a bis(sulfonyl)alkanol-containingpolythioether, prepolymer thereof, or metal ligand-containing prepolymeris terminated with thiol groups, a suitable curing agent is anunsaturated compound such as an acrylic or methacrylic ester of apolyol, unsaturated synthetic or naturally occurring resin compounds,triallyl cyanurate, and olefin terminated derivatives ofsulfur-containing compound such as polythioethers.

In certain embodiments, such as when amine and/or hydroxyl-terminatedbis(sulfonyl)alkanol-containing polythioethers, prepolymers thereof, oramine and/or hydroxyl-terminated metal ligand-containing prepolymers areused, compositions provided by the present disclosure may comprise anisocyanate curing agent such as a diisocyanate and/or triisocyanatecuring agent. Examples of suitable isocyanate curing agents includetoluene diisocyanate, and combinations of any of the foregoing.Isocyanate curing agents are commercially available and include, forexample, products under the tradenames Baydur® (Bayer MaterialScience),Desmodur® (Bayer MaterialScience), Solubond® (DSM), ECCO (ECCO),Vestanat® (Evonik), Irodur® (Huntsman), Rhodocoat™ (Perstorp), andVanchem® (V.T. Vanderbilt). In certain embodiments, a polyisocyanatecuring agent comprises isocyanate groups that are reactive with thiolgroups and that are less reactive with Michael acceptor groups. Examplesof useful curing agents that are reactive with amine groups includepolymeric polyisocyanates, non-limiting examples of which includepolyisocyanates having backbone linkages chosen from urethane linkages(—NH—C(O)—O—), thiourethane linkages (—NH—C(O)—S—), thiocarbamatelinkages (—NH—C(S)—O—), dithiourethane linkages (—NH—C(S)—S—), andcombinations of any of the foregoing.

In certain embodiments, an isocyanate curing agent comprises anisocyanate-functional polymer. Examples of suitableisocyanate-functional polymers include the isocyanate-functionalsulfur-containing polyformal polymers disclosed in U.S. patentapplication Ser. No. 13/051,002. In general, when used as a curingagent, an isocyanate-functional polymer has a molecular weight less thanabout 2,000 Daltons, less than about 1,500, Daltons, less than about1,000 Daltons, and in certain embodiments, less than about 500 Daltons.

In such compositions, an isocyanate curing agent may comprise about 0.5wt % to about 20 wt % of the composition, from about 1 wt % to about 10wt %, from about 2 wt % to about 8 wt %, from about 2 wt % to about 6 wt%, and in certain embodiments, from about 3 wt % to about 5 wt % of thecomposition, where wt % is based on the total solids weight of thecomposition.

In certain embodiments, such as when isocyanate-terminatedbis(sulfonyl)alkanol-containing polythioethers, prepolymers thereof, orisocyanate-terminated metal ligand-containing prepolymer are used,compositions provided by the present disclosure comprise an amine curingagent. Examples of useful curing agents that are reactive withisocyanate groups include diamines, polyamines, polythiols, and polyols,including those disclosed herein.

In certain embodiments, such as when Michael acceptor-terminatedbis(sulfonyl)alkanol-containing polythioethers, prepolymers thereof, orMichael acceptor-terminated metal ligand-containing prepolymer are used,compositions provided by the present disclosure comprise a curing agentselected from a monomeric thiol, a polythiol, a polyamine, and a blockedpolyamine.

Curing agents useful in compositions provided by the present disclosureinclude compounds that are reactive with the terminal groups of thebis(sulfonyl)alkanol-containing polythioether or metal ligand-containingprepolymer, such as compounds that are reactive with hydroxyl groups,alkenyl groups, epoxy groups, thiol groups, amine groups, or isocyanategroups.

Examples of useful curing agents that are reactive with hydroxyl groupsinclude diisocyanates and polyisocyanates, examples of which aredisclosed herein.

Examples of useful curing agents that are reactive with alkenyl groupsinclude dithiols and polythiols, examples of which are disclosed herein.

Polyalkoxysilyl-terminated bis(sulfonyl)alkanol-containingpolythioethers or metal ligand-containing prepolymers provided by thepresent disclosure can hydrolyze in the presence of water inducingself-polymerization via condensation. Catalysts for use withpolyalkoxysilyl-terminated bis(sulfonyl)alkanol-containing polythioetheror polyalkoxysilyl-terminated metal ligand-containing prepolymer,include organotitanium compounds such as tetraisopropoxy titanium,tetra-tert-butoxy titanium, titaniumdi(isopropoxy)bis(ethylacetoacetate), and titaniumdi(isopropoxy)bis(acetylacetoacetate); organic tin compounds dibutyltindilaurate, dibutyltin bisacetylacetoacetate, and tin octylate; metaldicarboxylates such as lead dioctylate; organozirconium compounds suchas zirconium tetraacetyl acetonate; and organoaluminum compounds such asaluminum triacetyl-acetonate. Other examples of suitable catalysts formoisture curing include diisopropoxy bis(ethyl acetoacetonate)titanium,diisopropoxy bis(acetyl acetonate)titanium, and dibutoxy bis(methylacetoacetonate)titanium. It can be appreciated that because the curingagent for polyalkoxysilyl-terminated bis(sulfonyl)alkanol-containingpolythioether or polyalkoxysilyl-terminated metal ligand-containingprepolymer, can be atmospheric moisture, it is not necessary to includea curing agent to a curable composition containingpolyalkoxysilyl-terminated bis(sulfonyl)alkanol-containing polythioetheror polyalkoxysilyl-terminated metal ligand-containing prepolymer.Therefore, compositions comprising polyalkoxysilyl-terminatedbis(sulfonyl)alkanol-containing polythioethers orpolyalkoxysilyl-terminated metal ligand-containing prepolymers and acuring agent for the polyalkoxysilyl group refer to atmosphericmoisture.

In certain embodiments in which a bis(sulfonyl)alkanol-containingpolythioether, prepolymer thereof, or metal ligand-containing prepolymeris terminated with epoxy groups, a suitable curing agent is a polythiol,polyalkylene, or polyamine. Other examples of useful curing agents thatare reactive with terminal epoxy groups include amines such asdiethylenetriamine (DTA), triethylenetetramine (TTA),tetraethylenepentamine (TEPA), diethylaminopropylamine (DEAPA),N-aminoethylpiperazine (N-AEP), isophoronediamine (IPDA),m-xylenediamine, diaminodiphenylmethane (DDM), diaminodiphenylsulfone(DDS); aromatic amines, ketimine; polyamines; polyamides; phenolicresins; anhydrides such phthalic anhydride, trimellitic anhydride,pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethyleneglycol bistrimellitate, glycerol tristrimellitate, maleic anhydride,tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride,endomethylene tetrahydrophthalic anhydride; polymercaptans;polysulfides; and other curing agents known to those skilled in the art.

Compositions provided by the present disclosure may contain from about90% to about 150% of the stoichiometric amount, from about 95% to about125%, and in certain embodiments, from about 95% to about 105% of theamount of the selected curing agent(s).

Additional Sulfur-Containing Prepolymers

In certain embodiments, compositions provided by the present disclosurecomprise, in addition to a bis(sulfonyl)alkanol-containingpolythioether, a prepolymer thereof, a metal-ligand containingprepolymer, or a reaction product of any one of the reactions disclosedherein, or a combination of any of the foregoing, one or more additionalsulfur-containing prepolymers. A sulfur-containing prepolymer can be anyprepolymer having at least one sulfur atom in the repeating unit,including, but not limited to, polymeric thiols, polythiols, thioethers,polythioethers, sulfur-containing polyformals, and polysulfides. A“thiol,” as used herein, refers to a compound comprising a thiol ormercaptan group, that is, an “SH” group, either as the sole functionalgroup or in combination with other functional groups, such as hydroxylgroups, as is the case with, for example, thioglycerols. A polythiolrefers to such a compound having more than one SH group, such as adithiol or higher functionality thiol. Such groups are typicallyterminal and/or pendant such that they have an active hydrogen that isreactive with other functional groups. A polythiol can comprise both aterminal and/or pendant sulfur (—SH) and a non-reactive sulfur atom (—S—or —S—S—). Thus, the term polythiol generally encompasses polythioethersand polysulfides.

Examples of additional sulfur-containing prepolymers useful incompositions provided by the present disclosure include, for example,those disclosed in U.S. Pat. Nos. 6,172,179, 6,509,418, and 7,009,032.In certain embodiments, compositions provided by the present disclosurecomprise a polythioether having the structure of Formula (30):—R¹—[—S—(CH₂)₂—O—[—R²—O—]_(m)—(CH₂)₂—S—R¹—]_(n)—  (30)wherein R¹ is selected from a C₂₋₆ alkanediyl, C₆₋₈ cycloalkanediyl,C₆₋₁₀ cycloalkanealkanediyl, —[(—CH₂—)_(s)—X—]_(q)—(—CH₂—)_(r)—, and—[(—CH₂—)_(s)—X—]_(q)—(CH₂—)_(r)— in which at least one —CH₂— unit issubstituted with a methyl group; R² is selected from C₂₋₆ alkanediyl,C₆₋₈ cycloalkanediyl, C₆₋₁₀ cycloalkanealkanediyl, and—[(—CH₂—)_(s)—X—]_(q)—(—CH₂—); X is selected from O, S, and —NR⁵—, whereR⁵ is selected from hydrogen and methyl; m is an integer from 0 to 10; nis an integer from 1 to 60; p is an integer from 2 to 6; q is an integerfrom 1 to 5, and r is an integer from 2 to 10. Such polythioethers aredescribed in U.S. Pat. No. 6,172,179 at col. 2, line 29 to col. 4, line34.

The one or more additional sulfur-containing polymers may bedifunctional or multifunctional, for example, having from 3 to 6terminal groups, or a mixture thereof.

In certain embodiments, compositions provided by the present disclosurecomprise from about 10 wt % to about 90 wt % of a sulfur-containingpolymer provided by the present disclosure, from about 20 wt % to about80 wt %, from about 30 wt % to about 70 wt %, and in certain embodimentsfrom about 40 wt % to about 60 wt %, where wt % is based on the totalweight of all non-volatile components of the composition (i.e., the dryweight).

As used herein, the term polysulfide refers to a polymer that containsone or more sulfide linkages, i.e., —S_(x)— linkages, where x is from 2to 4, in the polymer backbone and/or in pendant positions on the polymerchain. In certain embodiments, the polysulfide polymer will have two ormore sulfur-sulfur linkages. Suitable polysulfides are commerciallyavailable, for example, from Akzo Nobel and Toray Fine Chemicals underthe names Thiokol-LP and Thioplast®. Thioplast® products are availablein a wide range of molecular weights ranging, for example, from lessthan 1,100 to over 8,000, with molecular weight being the averagemolecular weight in grams per mole. In some cases, the polysulfide has anumber average molecular weight of 1,000 Daltons to 4,000 Daltons. Thecrosslink density of these products also varies, depending on the amountof crosslinking agent used. The —SH content, i.e., thiol or mercaptancontent, of these products can also vary. The mercaptan content andmolecular weight of the polysulfide can affect the cure speed of thepolymer, with cure speed increasing with molecular weight.

Sulfur-containing polyformal prepolymers useful in aerospace sealantapplications are disclosed, for example, in U.S. Application PublicationNo. 2012/0234205 and in U.S. Application Publication No. 2012/0238707.

In certain embodiments, the sulfur-containing polymer is selected from apolythioether and a polysulfide, and a combination thereof. In certainembodiments, a sulfur-containing polymer comprises a polythioether, andin certain embodiments, a sulfur-containing polymer comprises apolysulfide. A sulfur-containing polymer may comprise a mixture ofdifferent polythioethers and/or polysulfides, and the polythioethersand/or polysulfides may have the same or different functionality. Incertain embodiments, a sulfur-containing polymer has an averagefunctionality from 2 to 6, from 2 to 4, from 2 to 3, and in certainembodiments, from 2.05 to 2.5. For example, a sulfur-containing polymercan be selected from a difunctional sulfur-containing polymer, atrifunctional sulfur-containing polymer, and a combination thereof.

Compositions provided by the present disclosure may include one or morecatalysts. A catalyst can be selected as appropriate for the curingchemistry employed. In certain embodiments, for example, when curingthiol-terminated bis(sulfonyl)alkanol-containing polythioethers,prepolymers, or thiol-terminated metal-ligand containing prepolymers,and polyepoxides, the catalyst is an amine catalyst. A cure catalyst maybe present in an amount from 0.1 to 5 weight percent, based on the totalweight of the composition. Examples of suitable catalysts include1,4-diazabicyclo[2.2.2]octane (DABCO®, commercially available from AirProducts, Chemical Additives Division, Allentown, Pa.) and DMP-30® (anaccelerant composition including 2,4,6-tris(dimethylaminomethyl)phenol.

In certain embodiments, compositions provided by the present disclosurecomprise one or more than one adhesion promoters. A one or moreadditional adhesion promoter may be present in amount from 0.1 wt % to15 wt % of a composition, less than 5 wt %, less than 2 wt %, and incertain embodiments, less than 1 wt %, based on the total dry weight ofthe composition. Examples of adhesion promoters include phenolics, suchas Methylon® phenolic resin, and organosilanes, such as epoxy, mercaptoor amino functional silanes, such as Silquest® A-187 and Silquest®A-1100. Other useful adhesion promoters are known in the art.

Compositions provided by the present disclosure may comprise one or moredifferent types of filler. Suitable fillers include those commonly knownin the art, including inorganic fillers, such as carbon black andcalcium carbonate (CaCO₃), silica, polymer powders, and lightweightfillers. Suitable lightweight fillers include, for example, thosedescribed in U.S. Pat. No. 6,525,168. In certain embodiments, acomposition includes 5 wt % to 60 wt % of the filler or combination offillers, 10 wt % to 50 wt %, and in certain embodiments, from 20 wt % to40 wt %, based on the total dry weight of the composition. Compositionsprovided by the present disclosure may further include one or morecolorants, thixotropic agents, accelerators, fire retardants, adhesionpromoters, solvents, masking agents, or a combination of any of theforegoing. As can be appreciated, fillers and additives employed in acomposition may be selected so as to be compatible with each other aswell as the polymeric component, curing agent, and or catalyst. Examplesof electrically non-conductive fillers include materials such as, butnot limited to, calcium carbonate, mica, polyamide, fumed silica,molecular sieve powder, microspheres, titanium dioxide, chalks, alkalineblacks, cellulose, zinc sulfide, heavy spar, alkaline earth oxides,alkaline earth hydroxides, and the like.

In certain embodiments, compositions provided by the present disclosureinclude low density filler particles. As used herein, low density, whenused with reference to such particles means that the particles have aspecific gravity of no more than 0.7, in certain embodiments no morethan 0.25, and in certain embodiments, no more than 0.1. Suitablelightweight filler particles often fall within twocategories—microspheres and amorphous particles. The specific gravity ofmicrospheres may range from 0.1 to 0.7 and include, for example,polystyrene foam, microspheres of polyacrylates and polyolefins, andsilica microspheres having particle sizes ranging from 5 to 100 micronsand a specific gravity of 0.25 (Eccospheres®). Other examples includealumina/silica microspheres having particle sizes in the range of 5 to300 microns and a specific gravity of 0.7 (Fillite®), aluminum silicatemicrospheres having a specific gravity of from about 0.45 to about 0.7(Z-Light®), calcium carbonate-coated polyvinylidene copolymermicrospheres having a specific gravity of 0.13 (Dualite® 6001AE), andcalcium carbonate coated acrylonitrile copolymer microspheres such asDualite® E135, having an average particle size of about 40 μm and adensity of 0.135 g/cc (Henkel). Suitable fillers for decreasing thespecific gravity of the composition include, for example, hollowmicrospheres such as Expancel® microspheres (available from AkzoNobel)or Dualite® low density polymer microspheres (available from Henkel). Incertain embodiments, compositions provided by the present disclosureinclude lightweight filler particles comprising an exterior surfacecoated with a thin coating, such as those described in U.S. ApplicationPublication No. 2010/0041839 at paragraphs [0016]-[0052], the citedportion of which is incorporated herein by reference.

In certain embodiments, a low density filler comprises less than 2 wt %of a composition, less than 1.5 wt %, less than 1.0 wt %, less than 0.8wt %, less than 0.75 wt %, less than 0.7 wt % and in certainembodiments, less than 0.5 wt % of a composition, where wt % is based onthe total dry solids weight of the composition.

In certain embodiments, compositions provided by the present disclosurecomprise at least one filler that is effective in reducing the specificgravity of the composition. In certain embodiments, the specific gravityof a composition is from 0.8 to 1, 0.7 to 0.9, from 0.75 to 0.85, and incertain embodiments, is 0.8. In certain embodiments, the specificgravity of a composition is less than about 0.9, less than about 0.8,less than about 0.75, less than about 0.7, less than about 0.65, lessthan about 0.6, and in certain embodiments, less than about 0.55.

In certain embodiments, compositions provided by the present disclosurecomprise an electrically conductive filler. Electrical conductivity andEMI/RFI shielding effectiveness can be imparted to composition byincorporating conductive materials within the polymer. The conductiveelements can include, for example, metal or metal-plated particles,fabrics, meshes, fibers, and combinations thereof. The metal can be inthe form of, for example, filaments, particles, flakes, or spheres.Examples of metals include copper, nickel, silver, aluminum, tin, andsteel. Other conductive materials that can be used to impart electricalconductivity and EMI/RFI shielding effectiveness to polymer compositionsinclude conductive particles or fibers comprising carbon or graphite.Conductive polymers such as polythiophenes, polypyrroles, polyaniline,poly(p-phenylene) vinylene, polyphenylene sulfide, polyphenylene, andpolyacetylene can also be used. Electrically conductive fillers alsoinclude high band gap materials such as zinc sulfide and inorganicbarium compounds.

Other examples of electrically conductive fillers include electricallyconductive noble metal-based fillers such as pure silver; noblemetal-plated noble metals such as silver-plated gold; noble metal-platednon-noble metals such as silver plated cooper, nickel or aluminum, forexample, silver-plated aluminum core particles or platinum-plated copperparticles; noble-metal plated glass, plastic or ceramics such assilver-plated glass microspheres, noble-metal plated aluminum ornoble-metal plated plastic microspheres; noble-metal plated mica; andother such noble-metal conductive fillers. Non-noble metal-basedmaterials can also be used and include, for example, non-noblemetal-plated non-noble metals such as copper-coated iron particles ornickel plated copper; non-noble metals, e.g., copper, aluminum, nickel,cobalt; non-noble-metal-plated-non-metals, e.g., nickel-plated graphiteand non-metal materials such as carbon black and graphite. Combinationsof electrically conductive fillers can also be used to meet the desiredconductivity, EMI/RFI shielding effectiveness, hardness, and otherproperties suitable for a particular application.

The shape and size of the electrically conductive fillers used in thecompositions of the present disclosure can be any appropriate shape andsize to impart electrical conductivity and EMI/RFI shieldingeffectiveness to the cured composition. For example, fillers can be ofany shape generally used in the manufacture of electrically conductivefillers, including spherical, flake, platelet, particle, powder,irregular, fiber, and the like. In certain sealant compositions of thedisclosure, a base composition can comprise Ni-coated graphite as aparticle, powder or flake. In certain embodiments, the amount ofNi-coated graphite in a base composition can range from 40 wt % to 80 wt%, and in certain embodiments can range from 50 wt % to 70 wt %, basedon the total weight of the base composition. In certain embodiments, anelectrically conductive filler can comprise Ni fiber. Ni fiber can havea diameter ranging from 10 μm to 50 μm and have a length ranging from250 μm to 750 μm. A base composition can comprise, for example, anamount of Ni fiber ranging from 2 wt % to 10 wt %, and in certainembodiments, from 4 wt % to 8 wt %, based on the total weight of thebase composition.

Carbon fibers, particularly graphitized carbon fibers, can also be usedto impart electrical conductivity to compositions of the presentdisclosure. Carbon fibers formed by vapor phase pyrolysis methods andgraphitized by heat treatment and which are hollow or solid with a fiberdiameter ranging from 0.1 micron to several microns, have highelectrical conductivity. As disclosed in U.S. Pat. No. 6,184,280, carbonmicrofibers, nanotubes or carbon fibrils having an outer diameter ofless than 0.1 m to tens of nanometers can be used as electricallyconductive fillers. An example of graphitized carbon fiber suitable forconductive compositions of the present disclosure include Panex® 3OMF(Zoltek Companies, Inc., St. Louis, Mo.), a 0.921 m diameter round fiberhaving an electrical resistivity of 0.00055 Ω-cm.

The average particle size of an electrically conductive filler can bewithin a range useful for imparting electrical conductivity to apolymer-based composition. For example, in certain embodiments, theparticle size of the one or more fillers can range from 0.25 m to 250 m,in certain embodiments can range from 0.25 m to 75 m, and in certainembodiments can range from 0.25 m to 60 m. In certain embodiments,composition of the present disclosure can comprise Ketjenblack® EC-600JD (Akzo Nobel, Inc., Chicago, Ill.), an electrically conductive carbonblack characterized by an iodine absorption of 1,000 mg/g to 11,500 mg/g(J0/84-5 test method), and a pore volume of 480 cm³/100 g to 510 cm³/100g (DBP absorption, KTM 81-3504). In certain embodiments, an electricallyconductive carbon black filler is Black Pearls® 2000 (Cabot Corporation,Boston, Mass.).

In certain embodiments, electrically conductive polymers can be used toimpart electrical conductivity or modify the electrical conductivity ofcompositions of the present disclosure. Polymers having sulfur atomsincorporated into aromatic groups or adjacent to double bonds, such asin polyphenylene sulfide, and polythiophene, are known to beelectrically conductive. Other electrically conductive polymers include,for example, polypyrroles, polyaniline, poly(p-phenylene) vinylene, andpolyacetylene. In certain embodiments, the sulfur-containing polymersforming a base composition can be polysulfides and/or polythioethers. Assuch, the sulfur-containing polymers can comprise aromatic sulfur groupsand sulfur atoms adjacent to conjugated double bonds to enhance theelectrical conductivity of the compositions of the present disclosure.

Compositions of the present disclosure can comprise more than oneelectrically conductive filler and the more than one electricallyconductive filler can be of the same or different materials and/orshapes. For example, a sealant composition can comprise electricallyconductive Ni fibers, and electrically conductive Ni-coated graphite inthe form of powder, particles or flakes. The amount and type ofelectrically conductive filler can be selected to produce a sealantcomposition which, when cured, exhibits a sheet resistance (four-pointresistance) of less than 0.50 Ω/cm², and in certain embodiments, a sheetresistance less than 0.15 Ω/cm². The amount and type of filler can alsobe selected to provide effective EMI/RFI shielding over a frequencyrange of from 1 MHz to 18 GHz for an aperture sealed using a sealantcomposition of the present disclosure.

In certain embodiments, an electrically conductive base composition cancomprise an amount of electrically non-conductive filler ranging from 2wt % to 10 wt % based on the total weight of the base composition, andin certain embodiments, can range from 3 wt % to 7 wt %. In certainembodiments, a curing agent composition can comprise an amount ofelectrically non-conductive filler ranging from less than 6 wt % and incertain embodiments ranging from 0.5% to 4% by weight, based on thetotal weight of the curing agent composition.

Galvanic corrosion of dissimilar metal surfaces and the conductivecompositions of the present disclosure can be minimized or prevented byadding corrosion inhibitors to the composition, and/or by selectingappropriate conductive fillers. In certain embodiments, corrosioninhibitors include strontium chromate, calcium chromate, magnesiumchromate, and combinations thereof. U.S. Pat. No. 5,284,888 and U.S.Pat. No. 5,270,364 disclose the use of aromatic triazoles to inhibitcorrosion of aluminum and steel surfaces. In certain embodiments, asacrificial oxygen scavenger such as Zn can be used as a corrosioninhibitor. In certain embodiments, the corrosion inhibitor can compriseless than 10% by weight of the total weight of the electricallyconductive composition. In certain embodiments, the corrosion inhibitorcan comprise an amount ranging from 2% by weight to 8% by weight of thetotal weight of the electrically conductive composition. Corrosionbetween dissimilar metal surfaces can also be minimized or prevented bythe selection of the type, amount, and properties of the conductivefillers comprising the composition.

In certain embodiments, a bis(sulfonyl)alkanol-containing polythioetherand/or bis(sulfonyl)alkanol-containing polythioether prepolymer and/ormetal-ligand containing prepolymers may comprise from about 50 wt % toabout 90 wt % of a composition, from about 60 wt % to about 90 wt %,from about 70 wt % to about 90 wt %, and in certain embodiments, fromabout 80 wt % to about 90 wt % of the composition, where wt % is basedon the total dry solids weight of the composition.

A composition may also include any number of additives as desired.Examples of suitable additives include plasticizers, pigments,surfactants, adhesion promoters, thixotropic agents, fire retardants,masking agents, and accelerators (such as amines, including1,4-diazabicyclo[2.2.2]octane, DABCO®), and combinations of any of theforegoing. When used, the additives may be present in a composition inan amount ranging, for example, from about 0% to 60% by weight. Incertain embodiments, additives may be present in a composition in anamount ranging from about 25% to 60% by weight.

USES

Compositions provided by the present disclosure may be used, forexample, in sealants, coatings, encapsulants, and potting compositions.A sealant includes a composition capable of producing a film that hasthe ability to resist operational conditions, such as moisture andtemperature, and at least partially block the transmission of materials,such as water, fuel, and other liquid and gases. A coating compositionincludes a covering that is applied to the surface of a substrate to,for example, improve the properties of the substrate such as theappearance, adhesion, wettability, corrosion resistance, wearresistance, fuel resistance, and/or abrasion resistance. A pottingcomposition includes a material useful in an electronic assembly toprovide resistance to shock and vibration and to exclude moisture andcorrosive agents. In certain embodiments, sealant compositions providedby the present disclosure are useful, e.g., as aerospace sealants and aslinings for fuel tanks.

In certain embodiments, compositions, such as sealants, may be providedas multi-pack compositions, such as two-pack compositions, wherein onepackage comprises one or more thiol-terminated metal ligand-containingpolythioethers or thiol-terminated metal ligand-containing prepolymerprovided by the present disclosure and a second package comprises one ormore polyfunctional sulfur-containing epoxies provided by the presentdisclosure. Additives and/or other materials may be added to eitherpackage as desired or necessary. The two packages may be combined andmixed prior to use. In certain embodiments, the pot life of the one ormore mixed thiol-terminated polythioethers and epoxies is at least 30minutes, at least 1 hour, at least 2 hours, and in certain embodiments,more than 2 hours, where pot life refers to the period of time the mixedcomposition remains suitable for use as a sealant after mixing.

Compositions, including sealants, provided by the present disclosure maybe applied to any of a variety of substrates. Examples of substrates towhich a composition may be applied include metals such as titanium,stainless steel, aluminum, and alloys thereof, any of which may beanodized, primed, organic-coated or chromate-coated; epoxy; urethane;graphite; fiberglass composite; Kevlar®; acrylics; and polycarbonates.In certain embodiments, compositions provided by the present disclosuremay be applied to a coating on a substrate, such as a polyurethanecoating. In certain embodiments, compositions comprisingbis(sulfonyl)alkanol-containing polythioethers or metal-ligandcontaining prepolymers provided by the present disclosure exhibitenhanced adhesion to aluminum, aluminum oxide, anodized aluminum,titanium, titanium oxide, and/or Alodine® surfaces In particular,compositions comprising bis(sulfonyl)alkanol-containing polythioethersor metal-ligand containing prepolymers provided by the presentdisclosure exhibit enhanced adhesion to bare metal and to anodized metalsurfaces.

Compositions provided by the present disclosure may be applied directlyonto the surface of a substrate or over an underlayer by any suitablecoating process known to those of ordinary skill in the art.

Furthermore, methods are provided for sealing an aperture utilizing acomposition provided by the present disclosure. These methods comprise,for example, applying a composition provided by the present disclosureto a surface to seal an aperture, and curing the composition. In certainembodiments, a method for sealing an aperture comprises (a) applying asealant composition provided by the present disclosure to one or moresurfaces defining an aperture, and (b) curing the applied sealantcomposition, to provide a sealed aperture.

In certain embodiments, apertures sealed with a sealant composition ofthe present disclosure are provided.

In certain embodiments, a composition may be cured under ambientconditions, where ambient conditions refers to a temperature from 20° C.to 25° C., and atmospheric humidity. In certain embodiments, acomposition may be cured under conditions encompassing a temperaturefrom a 0° C. to 100° C. and humidity from 0% relative humidity to 100%relative humidity. In certain embodiments, a composition may be cured ata higher temperature such as at least 30° C., at least 40° C., and incertain embodiments, at least 50° C. In certain embodiments, acomposition may be cured at room temperature, e.g., 25° C. In certainembodiments, a composition may be cured upon exposure to actinicradiation, such as ultraviolet radiation. As will also be appreciated,the methods may be used to seal apertures on aerospace vehiclesincluding aircraft and aerospace vehicles.

In certain embodiments, the composition achieves a tack-free cure inless than about 2 hours, less than about 4 hours, less than about 6hours, less than about 8 hours, and in certain embodiments, less thanabout 10 hours, at a temperature of less than about 200° F.

The time to form a viable seal using curable compositions of the presentdisclosure can depend on several factors as can be appreciated by thoseskilled in the art, and as defined by the requirements of applicablestandards and specifications. In general, curable compositions of thepresent disclosure develop adhesion strength within 24 hours to 30hours, and 90% of full adhesion strength develops from 2 days to 3 days,following mixing and application to a surface. In general, full adhesionstrength as well as other properties of cured compositions of thepresent disclosure becomes fully developed within 7 days followingmixing and application of a curable composition to a surface.

Cured compositions disclosed herein, such as cured sealants, exhibitproperties acceptable for use in aerospace applications. In general, itis desirable that sealants used in aviation and aerospace applicationsexhibit the following properties: peel strength greater than 20 poundsper linear inch (pli) on Aerospace Material Specification (AMS) 3265Bsubstrates determined under dry conditions, following immersion in JRFType I for 7 days, and following immersion in a solution of 3% NaClaccording to AMS 3265B test specifications; tensile strength between 300pounds per square inch (psi) and 400 psi; tear strength greater than 50pounds per linear inch (pli); elongation between 250% and 300%; andhardness greater than 40 Durometer A. These and other cured sealantproperties appropriate for aviation and aerospace applications aredisclosed in AMS 3265B, the entirety of which is incorporated herein byreference. It is also desirable that, when cured, compositions of thepresent disclosure used in aviation and aircraft applications exhibit apercent volume swell not greater than 25% following immersion for oneweek at 60° C. (140° F.) and ambient pressure in JRF Type I. Otherproperties, ranges, and/or thresholds may be appropriate for othersealant applications.

In certain embodiments, therefore, compositions provided by the presentdisclosure are fuel-resistant. As used herein, the term “fuel resistant”means that a composition, when applied to a substrate and cured, canprovide a cured product, such as a sealant, that exhibits a percentvolume swell of not greater than 40%, in some cases not greater than25%, in some cases not greater than 20%, in yet other cases not morethan 10%, after immersion for one week at 140° F. (60° C.) and ambientpressure in Jet Reference Fluid (JRF) Type I according to methodssimilar to those described in ASTM D792 (American Society for Testingand Materials) or AMS 3269 (Aerospace Material Specification). JetReference Fluid JRF Type I, as employed for determination of fuelresistance, has the following composition: toluene: 28%±1% by volume;cyclohexane (technical): 34%±1% by volume; isooctane: 38%±1% by volume;and tertiary dibutyl disulfide: 1%±0.005% by volume (see AMS 2629,issued Jul. 1, 1989, §3.1.1, etc., available from SAE (Society ofAutomotive Engineers)).

In certain embodiments, compositions provided herein provide a curedproduct, such as a sealant, exhibiting a elongation of at least 100% anda tensile strength of at least 400 psi when measured in accordance withthe procedure described in AMS 3279, §3.3.17.1, test procedure AS5127/1,§7.7.

In certain embodiments, compositions provide a cured product, such as asealant, that exhibits a lap shear strength of greater than 200 psi,such as at least 220 psi, at least 250 psi, and, in some cases, at least400 psi, when measured according to the procedure described in SAEAS5127/1 paragraph 7.8.

In certain embodiments, a cured sealant comprising a compositionprovided by the present disclosure meets or exceeds the requirements foraerospace sealants as set forth in AMS 3277.

Apertures, including apertures of aerospace vehicles, sealed withcompositions provided by the present disclosure are also disclosed.

In certain embodiments, a cured sealant provided by the presentdisclosure exhibits the following properties when cured for 2 days atroom temperature, 1 day at 140 OF and 1 day at 200° F.: a dry hardnessof 49, a tensile strength of 428 psi, and an elongation of 266%; andafter 7 days in JRF Type I, a hardness of 36, a tensile strength of 312psi, and an elongation of 247%.

In certain embodiments, compositions provided by the present disclosureexhibit a Shore A hardness (7-day cure) greater than 10, greater than20, greater than 30, and in certain embodiments, greater than 40; atensile strength greater than 10 psi, greater than 100 psi, greater than200 psi, and in certain embodiments, greater than 500 psi; an elongationgreater than 100%, greater than 200%, greater than 500%, and in certainembodiments, greater than 1,000%; and a swell following exposure to JRFType I (7 days) less than 20%.

Cured sealants prepared from metal ligand-containing prepolymer providedby the present disclosure exhibit enhanced tensile strength and enhancedadhesion to metal and/or metal oxide surfaces. The metal ligandsincorporated into the backbone of the prepolymer can serve aspolydentate ligands in metal chelates.

EXAMPLES

Embodiments provided by the present disclosure are further illustratedby reference to the following examples, which describe the synthesis,properties, and uses of certain bis(sulfonyl)alkanol-containingpolythioethers and metal-ligand containing prepolymers and compositionscomprising bis(sulfonyl)alkanol-containing polythioethers ormetal-ligand containing prepolymers. It will be apparent to thoseskilled in the art that many modifications, both to materials, andmethods, may be practiced without departing from the scope of thedisclosure.

Example 1 Thiol-Terminated Polythioether

1,8-Dimercapto-3,6-dioxaoctane (DMDO; 1995.60 g; 10.95 moles) wascharged into a 5-liter, 4-necked round-bottomed flask. The flask wasequipped with a gas adapter for nitrogen, a paddle stirrer, and atemperature probe. The flask was flushed with nitrogen and the contentsheated to 60° C. while stirring. A free radical initiator Vazo®-67 (0.41g) was added into to the flask. Diethylene glycol divinyl ether (1154.51g, 7.30 moles) was introduced into the reaction mixture over a period of6.25 h during which time a temperature of 60° C. to 65° C. wasmaintained. The reaction temperature was raised to 77° C. and twoportions of Vazo®-67 (0.045 g each) were added with an interval of 3 h.The reaction mixture was heated at 94° C. for 2 h, cooled to 66° C., andevacuated at 66° C. to 74° C./15 mm Hg for 1 h.

The resulting polymer, a dithiol, had a mercaptan equivalent weight of430.

Example 2 Thiol-Terminated Bis(Sulfonyl)Alkanol-Containing Polythioether

The dithiol of Example 1 (55.04 g; 0.064 mole) was charged into a250-mL, 3-necked round-bottomed flask. The flask was equipped with a gasadapter for nitrogen and a paddle stirrer. The contents were evacuatedat 7 mm for 30 min and the vacuum was released under nitrogen. Understirring, base catalyst DBU (1,8-diazabicycloundec-7-ene; 0.013 g) wasadded followed by ethanol (10 g) and the flask equipped with atemperature probe. Under cooling (with a water bath), a solution of1,3-bis(vinylsulfonyl)-2-propanol (7.69 g; 0.032 mole) intetrahydrofuran (90 g) was dropped over a period of 2 h at temperaturefrom 19° C. to 20° C. The water bath was removed and the reactantsstirred at ambient temperature for an additional 2 h. The mercaptanequivalent was used to determine when the reaction was complete. Afterthe solvents were removed, a liquid difunctional polymer was providedhaving a mercaptan equivalent weight of 1,166 and a viscosity of 81poise.

Example 3 Thiol-Terminated Bis(Sulfonyl)Alkanol-Containing PolythioetherPrepolymer

The dithiol of Example 2 (62 g; 0.0177 mole) was charged into a 250-mL,3-necked round-bottomed flask. While stirring, a solution oftriallylcyanurate (TAC) (0.93 g; 0.0037 mole) and diethylene glycoldivinyl ether (0.22 g; 0.0014 mole) in toluene (1.0 g) were introducedinto the reaction mixture and the contents were heated at 77° C. Sevenportions (0.016 g each) of radical initiator Vazo®-67 were added at aninterval of 1 h to complete the reaction. Removal of solvents undervacuum provided a polymer having theoretical thiol functionality of2.21, a mercaptan equivalent weight of 1,659; and a viscosity of 195poise.

Example 4 Bis(Sulfonyl)Alkanol-Containing Polythioether Sealant

The prepolymer of Example 3 (14.93 g; 0.009 equivalent) and calciumcarbonate (Socal® N2R; 4.48 g) were charged into a mixing cup (capacity:60 g) of a Hauschild mixer (model: DAC 600 FVZ). The contents werecombined by hand mixing and then mixed in Hauschild mixer for 30 seconds(speed: 2300 RPM). The contents were again blended by hand and thenmixed in the Hauschild mixer for another 30 seconds. An epoxyaccelerator S-5304 (available from PPG Aerospace; 3.60 g, 0.009equivalent) was added. The contents were combined by hand mixing andthen mixed in a Hauschild mixer for 30 seconds. A base catalyst DABCO33-LV (0.12 g) was added. The contents were hand mixed and then mixed ina Hauschild mixer for 30 seconds.

Part of the mix was used to make a cure plug for hardness and remainingwas used to make adhesion specimens (approximate dimension: 4 cm×1.4cm×0.3 cm) on seven surfaces: Scotch-Brite® treated bare aluminum;Mil-C-27725; Scotch-Brite® treated Titanium B; Scotch-Brite® treatedTitanium C; Alodine® 1200; Anodized SAA and Anodized CAA. All specimenswere subjected to a cure cycle of room temperature/20 h; 60° C./27 h.After the samples were cured, the hardness was 40 (Shore A). Theadhesion, estimated by peeling/cutting the cured sealant from the metalsurface, for six out of seven surfaces was very good (100% cohesivefailure); however, the cured specimen did not adhere to Alodine® 1200(0% cohesive failure).

Example 5 Thiol-Terminated Bis(Sulfonyl)Alkanol-Containing DifunctionalPolythioether

The dithiol of Example 1 (636.40 g; 0.74 mole) was charged into a2-liter, 4-necked round-bottomed flask. The flask was equipped with agas adapter for nitrogen and a paddle stirrer. The contents wereevacuated at 8 mm for 1 h and the vacuum was released under nitrogen.While stirring, ethanol (116 g) was added followed by base catalyst DBU(0.145 g) and the flask was equipped with a temperature probe. Undercooling (with a water bath), a solution of1,3-bis(vinylsulfonyl)-2-propanol (88.91 g; 0.37 mole) intetrahydrofuran (1.04 kg) was dropped over a period of about 2 h attemperature from 23° C. to 27° C. The mercaptan equivalent was used todetermine the progress of the reaction. The water bath was removed andthe reactants stirred at room temperature for an additional 3 h. Removalof solvents provided a difunctional polymer having a mercaptanequivalent weight of 1,296 and a viscosity of 107 poise.

Example 6 Thiol Terminated Bis(Sulfonyl)Alkanol-Containing PolythioetherPrepolymer

The difunctional polymer of Example 5 (725.29 g; 0.2798 mole) wascharged into a 2-liter, 4-necked round-bottomed flask. The flask wasequipped with a gas adapter for nitrogen and a paddle stirrer. Thecontents were flushed with nitrogen. While stirring, a solution oftriallylcyanurate (10.22 g; 0.041 mole) and diethylene glycol divinylether (0.49 g; 0.0031 mole) in toluene (5.0 mL) was introduced to thereaction mixture and the contents were heated at 70° C. Fifteen portions(0.084 g each) of radical initiator Vazo®-67 were added at intervals of1 h to complete the reaction. Removal of solvents under vacuum provideda polymer having a theoretical functionality of 2.21, mercaptanequivalent weight of 1675 and viscosity of 238 poise.

Example 7 Bis(Sulfonyl)Alkanol-Containing Polythioether Sealant

The prepolymer of Example 6 (30 g; 0.0179 equivalent) and calciumcarbonate (Socal® N2R; 9.00 g) were charged into a mixing cup (capacity:100 g) of a Hauschild mixer. The contents were handmixed and mixed inHauschild mixer for 30 seconds (speed: 2300 RPM). The contents weresubjected to two rounds of handmixing and further mixing in theHauschild mixer for 4 min. The contents were cooled to ambienttemperature. An epoxy accelerator, S-5304 (available from PPG Aerospace;7.16 g, 0.0179 equivalent), was added. The contents were subjected totwo rounds of handmixing and further mixing in the Hauschild mixer for30 seconds. Base catalyst DABCO 33-LV (0.24 g) was added. The contentswere handmixed, mixed further in the Hauschild mixer for 30 seconds andpoured in a grid to make a flowout (approximate dimension: length: 6inches; width: 3.2 inches; thickness: 0.1 inches). The sealant specimenwas subjected to a cure cycle of room temperature/7 days; followed bycuring at 140° F./24 h. The cured sealant had a hardness of 48 Shore A,a tensile strength of 373 psi, and an elongation of 472%.

Comparative Example 1

Permapol® 3.1E polymer (10 g, a thiol-terminated polythioetherprepolymer, commercially available from PRC-Desoto International,Sylmar, Calif.) and calcium carbonate (5.0 g) were mixed in Hauschildmixer for 30 seconds at 2300 rpm. An accelerator (S-5304, 2.6 g, anepoxy paste, commercially available from PRC-Desoto International,Sylmar, Calif.), and a catalyst (triethylenediamine; 0.08 g) weresequentially added and mixed. Samples were applied on various substratesincluding anodized CAA, anodized SAA, Mil C-27725, Alodine® 1200,Titanium C, bare aluminum, and Scotch-Brite® treated bare aluminum, andcured at room temperature for 24 hours followed by curing for 48 hoursat 140° F. The percent of cohesive adhesion was measured by peeling thesample from the substrates. Each of the samples exhibited 0% cohesivefailure.

Example 8 Density Functional Theory Calculation

The Gibbs free energy of interaction of various functional groups with aAl₄O₆ cluster (Li et al., “Structural determination of (Al₂O₃)_(n)(n=1-7) clusters based on density functional calculation,” Computationaland Theoretical Chemistry 2012, 996, 125-131) representing an aluminumoxide surface of a representative aerospace substrate was calculatedusing density functional theory (DFT) based method. All structures wereoptimized using Gaussian09/B3LYP/6-31g(d) and vibrational frequency wascalculated at the same level of theory to confirm that the structuresare at local minimum. A single point energy calculation with a CPCMsalvation scheme was used to calculate the energy in a waterenvironment. The Gibbs free energy of the interaction was calculatedunder standard conditions of pressure and temperature (1 atm and 25° C.)without correction.

Various functional groups were analyzed for their inherent properties,including energy of HOMO (highest occupied molecular orbital), LUMO(lowest unoccupied molecular orbital), and energy gap between HOMO andLUMO. Typically, functional groups with higher HOMO energy are moreelectron donating, and those with lower LUMO energy are more electronaccepting. Comparing various functional groups in Table1,3-hydroxy-1,2-dimethylpyridin-4(1H)-one (HOPO) has highest HOMOenergy, indicating HOPO is most electron donating. The functional groupbis(sulfonyl)-2-prpanol (BSP), on the other hand, has the lowest HOMOenergy, indicating it is least electron donating.

TABLE 1 Calculated properties of various functional groups HOMO LUMO GapCompounds (ev) (ev) (ev)

−7.02 −0.62 6.40

−7.54 0.62 8.16

−5.39 −0.45 4.95

The interaction between various functional groups and an aluminum oxidecluster was determined. The Gibbs free energy of interaction in the gasphase (ΔG_(g)) as well as in water (ΔG_(w)) was calculated and theresults are shown in FIG. 1, along with contribution from enthalpy (ΔH)of the reaction. In FIG. 1, more negative ΔG corresponds to a morestable complex or a stronger interaction between the functional groupand aluminum oxide. BSP and HOPO have a stronger interaction thanacetoacetate with aluminum oxide in the gas phase as well as in asimulated water environment. Acetoacetate binds to Al₄O₆ throughcoordination of electron rich carbonyl oxygen (in acetoacetate) withelectron deficient aluminum (in Al₄O₆). HOPO interacts with Al₄O₆ as abi-dentate ligand: i.e., carbonyl oxygen (in HOPO) binds to aluminum (inAl₄O₆) and the hydroxyl group (in HOPO) is hydrogen bonded with oxygen(in Al₄O₆). A tri-dentate binding mode for BSP with Al₄O₆ wasidentified: two sulfonyl groups (in BSP) bind to two aluminum atoms (inAl₄O₆) in addition to the hydrogen bond between hydroxyl group (in BSP)and oxygen atom (in Al₄O₆). Even though BSP is not very electrondonating (as shown by the low HOMO energy in Table 1), strong bindingwith Al₄O₆ with three coordination sites is nevertheless observed.

In conclusion, the BSP functional group was shown to bind to aluminumoxide through tri-dentate mode, resulting in very strong interaction(adhesion). Unlike other strong binding ligands such as HOPO, BSP isdifficult to oxidize and is expected to have good stability. Structureswith binding motifs similar to that of BSP can also lead to strongbinding toward aluminum oxide.

Similar methods may be used to identify other metal ligands appropriatefor enhancing adhesion to a particular metal surface and that may beincorporated into the backbone of a prepolymer and/or provided as aterminal group of a prepolymer as described in the present disclosure.

Finally, it should be noted that there are alternative ways ofimplementing the embodiments disclosed herein. Accordingly, the presentembodiments are to be considered as illustrative and not restrictive.Furthermore, the claims are not to be limited to the details givenherein, and are entitled to their full scope and equivalents thereof.

What is claimed is:
 1. A metal ligand-containing prepolymer comprising ametal ligand incorporated into a backbone of the prepolymer, wherein theprepolymer comprises a moiety of Formula (26):-A-R^(9′)L-R^(9′)A-  (26) wherein, each R^(9′) is independently a moietyderived from the reaction of R⁹ of a metal chelating agent R⁹-L-R⁹ witha thiol group, wherein each R⁹ comprises a terminal group reactive witha thiol; and L comprises a metal ligand; each A is independently amoiety of Formula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12) wherein, R¹is —(CH₂)₂—O—(CH₂)₂—O—(CH₂)₂—; p is 2; R² is —(CH₂)₂—; m is 2; and n isan integer from 1 to
 60. 2. The prepolymer of claim 1, wherein the metalchelating agent comprises a bis(sulfonyl)alkanol, a hydroxypyridinone,an acetylacetonate, or a combination of any of the foregoing.
 3. Theprepolymer of claim 1, wherein the metal ligand comprises a moiety ofFormula (25a), Formula (25b), Formula (25c), Formula (25d), Formula(25e), or a combination of any of the foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e) wherein, —X— is independently selected from —C(O)—or —S(O)₂—; each n is independently selected from 1, 2, and 3; and R⁵ isa C₁₋₃ alkane-diyl.
 4. The prepolymer of claim 3, wherein, each X isselected from —C(O)— and —S(O)₂—; and each n is
 1. 5. A metalligand-containing prepolymer comprising a metal ligand incorporated intoa backbone of the prepolymer wherein the prepolymer comprises a metalligand-containing polythioether of Formula (28a), a metalligand-containing polythioether of Formula (28b), or a combinationthereof:R⁶-A-[-R^(9′)-L-R^(9′)-A-]_(N)—R⁶  (28a){R⁶-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′—}_(z)B  (28b) wherein, N is aninteger from 1 to 10; each R^(9′) is independently a moiety derived fromthe reaction of R⁹ of a metal chelating agent R⁹-L-R⁹ with a thiolgroup, wherein each R⁹ comprises a terminal group reactive with a thiol;and L comprises a metal ligand; each A is independently a moiety ofFormula (12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12) wherein, R¹is —(CH₂)₂—O—(CH₂)₂—O—(CH₂)₂—; p is 2; R² is —(CH₂)₂—; m is 2; and n isan integer from 1 to 60; B represents a core of a z-valentpolyfunctionalizing agent B(—V)_(z) wherein: z is an integer from 3 to6; each V is a group comprising a terminal group reactive with terminalthiol groups; and each —V′— is derived from the reaction of —V with athiol; and each R⁶ independently is selected from hydrogen and a moietyhaving a terminal reactive group.
 6. The prepolymer of claim 5, whereineach R⁶ is hydrogen.
 7. The prepolymer of claim 5, wherein each R⁶ isthe same and the terminal reactive group is selected from —SH, —CH═CH₂,—NH₂, —OH, an epoxy group, a polyalkoxysilyl group, an isocyanate group,and a Michael acceptor group.
 8. The prepolymer of claim 5, wherein,B(—V)_(z) comprises triallyl cyanurate, which has the structure:

z is 3; each —V is —O—CH₂—CH═CH₂; each —V′— is —O—(CH₂)₃—; and B has thestructure:


9. The prepolymer of claim 6, wherein the metal ligand comprises amoiety of Formula (25a), Formula (25b), Formula (25c), Formula (25d),Formula (25e), or a combination of any of the foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e) wherein, —X— is independently selected from —C(O)—or —S(O)₂—; each n is independently selected from 1, 2, and 3; and R⁵ isa C₁₋₃ alkane-diyl.
 10. A thiol-terminated metal ligand-containingpolythioether comprising the reaction product of reactants comprising:(a) a thiol-terminated polythioether comprising a thiol-terminatedpolythioether of Formula (18a), a thiol-terminated polythioether ofFormula (18b), or a combination thereof:HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—SH  (18a){HS—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—V′—}_(z)B  (18b)wherein, R¹ is —(CH₂)₂—O—(CH₂)₂—O—(CH₂)₂—; p is 2; R² is —(CH₂)₂—; m is2; n is an integer from 1 to 60; and B represents a core of a z-valentpolyfunctionalizing agent B(—V)_(z) wherein: z is an integer from 3 to6; each V is a group comprising a terminal group reactive with terminalthiol groups; and each —V′— is derived from the reaction of —V with athiol; and (b) a metal chelating agent R⁹-L-R⁹, wherein, each R⁹independently comprises a terminal group reactive with a thiol; and-L-comprises a metal ligand.
 11. The polythioether of claim 10, whereinthe metal ligand comprises a moiety of Formula (25a), Formula (25b),Formula (25c), Formula (25d), Formula (25e), or a combination of any ofthe foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e) wherein, —X— is independently selected from —C(O)—or —S(O)₂—; each n is independently selected from 1, 2, and 3; and R⁵ isa C₁₋₃ alkane-diyl.
 12. The polythioether of claim 10, wherein the metalchelating agent comprises a bis(sulfonyl)alkanol, a hydroxypyridinone,an acetylacetonate, or a combination of any of the foregoing.
 13. Thepolythioether of claim 10, wherein, B(—V)_(z) comprises triallylcyanurate, which has the structure:

z is 3; each —V is —O—CH₂—CH═CH₂; each —V′— is —O—(CH₂)₃—; and B has thestructure:


14. An alkenyl-terminated metal ligand-containing polythioetherprepolymer comprising the reaction product of reactants comprising: (a)a thiol-terminated metal ligand-containing polythioether comprising athiol-terminated metal ligand-containing polythioether of Formula (29a),a thiol-terminated metal ligand-containing polythioether of Formula(29b), or a combination thereof:H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-H  (29a){H-A-[-R^(9′)-L-R^(9′)-A-]_(N)-V′-}_(z)B  (29b) wherein: N is an integerfrom 1 to 10; each R^(9′) is independently a moiety derived from thereaction of R⁹ of a metal chelating agent R⁹-L-R⁹ with a thiol group,wherein each R⁹ comprises a terminal group reactive with a thiol; and Lcomprises a metal ligand; each A is independently a moiety of Formula(12):—S—R¹—[—S—(CH₂)_(p)—O—(R²—O)_(m)—(CH₂)₂—S—R¹—]_(n)—S—  (12) wherein, R¹is —(CH₂)₂—O—(CH₂)₂—O—(CH₂)₂—; p is 2; R² is —(CH₂)₂—; m is 2; and n isan integer from 1 to 60; B represents a core of a z-valent,alkenyl-terminated polyfunctionalizing agent B(—V)_(z) wherein: z is aninteger from 3 to 6; and each V is a group comprising a terminal alkenylgroup; and each —V′— is derived from the reaction of —V with a thiol;and (b) a polyalkenyl compound.
 15. The polythioether prepolymer ofclaim 14, wherein the metal ligand comprises a moiety of Formula (25a),Formula (25b), Formula (25c), Formula (25d), Formula (25e), or acombination of any of the foregoing:—X—(CH₂)_(n)—CH(—OH)—  (25a)—X—(CH₂)_(n)—CH(—OH)—(CH₂)_(n)—X—  (25b)—CH(—OH)—(CH₂)_(n)—X—(CH₂)_(n)—CH(—OH)—  (25c)—CH(—OH)—R⁵—CH(—OH)—  (25d)—C(O)—R⁵—C(O)—  (25e) wherein, —X— is independently selected from —C(O)—or —S(O)₂—; each n is independently selected from 1, 2, and 3; and R⁵ isa C₁₋₃ alkane-diyl.
 16. The polythioether prepolymer of claim 14,wherein the polyalkenyl compound comprises a divinyl ether, analkenyl-terminated polyfunctionalizing agent, or a combination thereof.17. The polythioether prepolymer of claim 14, wherein, B(—V)_(z)comprises triallyl cyanurate, which has the structure:

z is 3; each —V is —O—CH₂—CH═CH₂; each —V′— is —O—(CH₂)₃—; and B has thestructure:


18. A composition comprising the metal ligand-containing prepolymer ofclaim
 1. 19. The composition of claim 18, comprising a curing agent. 20.The composition of claim 18, formulated as a sealant.
 21. A curedsealant prepared using the composition of claim
 20. 22. A compositioncomprising the metal ligand-containing prepolymer of claim
 5. 23. Thecomposition of claim 22, comprising a curing agent.
 24. The compositionof claim 22, formulated as a sealant.
 25. A cured sealant prepared usingthe composition of claim
 24. 26. A composition comprising the metalligand-containing prepolymer of claim
 10. 27. The composition of claim26, comprising a curing agent.
 28. The composition of claim 26,formulated as a sealant.
 29. A cured sealant prepared using thecomposition of claim
 28. 30. A composition comprising the metalligand-containing prepolymer of claim
 14. 31. The composition of claim30, comprising a curing agent.
 32. The composition of claim 30,formulated as a sealant.
 33. A cured sealant prepared using thecomposition of claim 32.